Methods and apparatus for cardiac valve repair

ABSTRACT

The methods, devices, and systems are provided for performing endovascular repair of atrioventricular and other cardiac valves in the heart. Regurgitation of an atrioventricular valve, particularly a mitral valve, can be repaired by modifying a tissue structure selected from the valve leaflets, the valve annulus, the valve chordae, and the papillary muscles. These structures may be modified by suturing, stapling, snaring, or shortening, using interventional tools which are introduced to a heart chamber. Preferably, the tissue structures will be temporarily modified prior to permanent modification. For example, opposed valve leaflets may be temporarily grasped and held into position prior to permanent attachment.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.09/544,930, filed Apr. 7, 2000, now U.S Pat. No. 6,629,534, whichclaimed the benefit under 35 USC 119(e) of U.S. Provisional ApplicationNo. 60/128,690, filed on Apr. 9, 1999 under 37 CFR §1.78(a). The fulldisclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to medical methods, devices, andsystems. In particular, the present invention relates to methods,devices, and systems for the endovascular or minimally invasive surgicalrepair of the atrioventricular valves of the heart, particularly themitral valve.

Mitral valve regurgitation is characterized by retrograde flow from theleft ventricle of a heart through an incompetent mitral valve into theleft atrium. During a normal cycle of heart contraction (systole), themitral valve acts as a check valve to prevent flow of oxygenated bloodback into the left atrium. In this way, the oxygenated blood is pumpedinto the aorta through the aortic valve. Regurgitation of the valve cansignificantly decrease the pumping efficiency of the heart, placing thepatient at risk of severe, progressive heart failure.

Mitral valve regurgitation can result from a number of differentmechanical defects in the mitral valve. The valve leaflets, the valvechordae which connect the leaflets to the papillary muscles, or thepapillary muscles themselves may be damaged or otherwise dysfunctional.Commonly, the valve annulus may be damaged, dilated, or weakenedlimiting the ability of the mitral valve to close adequately against thehigh pressures of the left ventricle.

The most common treatments for mitral valve regurgitation rely on valvereplacement or strengthening of the valve annulus by implanting amechanical support ring or other structure. The latter is generallyreferred to as valve annuloplasty. A recent technique for mitral valverepair which relies on suturing adjacent segments of the opposed valveleaflets together is referred to as the “bow-tie” or “edge-to-edge”technique. While all these techniques can be very effective, theyusually rely on open heart surgery where the patient's chest is opened,typically via a sternotomy, and the patient placed on cardiopulmonarybypass. The need to both open the chest and place the patient on bypassis traumatic and has associated morbidity.

For these reasons, it would be desirable to provide alternative andadditional methods, devices, and systems for performing the repair ofmitral and other cardiac valves, particularly the tricuspid valve whichis the other atrioventricular valve. Such methods, devices, and systemsshould preferably not require open chest access and be capable of beingperformed endovascularly, i.e., using devices which are advanced to theheart from a point in the patient's vasculature remote from the heart.Still more preferably, the methods, devices, and systems should notrequire that the heart be bypassed, although the methods, devices, andsystems should be useful with patients who are bypassed and/or whoseheart may be temporarily stopped by drugs or other techniques. At leastsome of these objectives will be met by the inventions describedhereinbelow.

2. Description of the Background Art

Minimally invasive and percutaneous techniques for coapting andmodifying mitral valve leaflets to treat mitral valve regurgitation aredescribed in WO 98/35638; WO 99/00059; WO 99/01377; and WO 00/03759.

Dec and Fuster (1994) N. Engl. J. Med. 331:1564-1575 and Alvarez et al.(1996) J. Thorac. Cardiovasc. Surg. 112:238-247 are review articlesdiscussing the nature of and treatments for dilated cardiomyopathy.

Maisano et al. (1998) Eur. J. Cardiothorac. Surg. 13:240-246; Fucci etal. (1995) Eur. J. Cardiothorac. Surg. 9:621-627; and Umana et al.(1998) Ann. Thorac. Surg. 66:1640-1646, describe open surgicalprocedures for performing “edge-to-edge” or “bow-tie” mitral valverepair where edges of the opposed valve leaflets are sutured together tolessen regurgitation.

Mitral valve annuloplasty is described in the following publications.Bach and Boiling (1996) Am. J. Cardiol. 78:966-969; Kameda et al. (1996)Ann. Thorac. Surg. 61:1829-1832; Bach and Bolling (1995) Am. Heart J.129:1165-1170; and Bolling et al. (1995) 109:676-683. Linear segmentalannuloplasty for mitral valve repair is described in Ricchi et al.(1997) Ann. Thorac. Surg. 63:1805-1806. Tricuspid valve annuloplasty isdescribed in McCarthy and Cosgrove (1997) Ann. Thorac. Surg. 64:267-268;Tager et al. (1998) Am. J. Cardiol. 81:1013-1016; and Abe et al. (1989)Ann. Thorac. Surg. 48:670-676.

Percutaneous transluminal cardiac repair procedures are described inPark et al. (1978) Circulation 58:600-608; Uchida et al. (1991) Am.Heart J. 121: 1221-1224; and Ali Khan et al. (1991) Cathet. Cardiovasc.Diagn. 23:257-262.

Endovascular cardiac valve replacement is described in U.S. Pat. Nos.5,840,081; 5,411,552; 5,554,185; 5,332,402; 4,994,077; and 4,056,854.See also U.S. Pat. No. 3,671,979 which describes a catheter fortemporary placement of an artificial heart valve.

Other percutaneous and endovascular cardiac repair procedures aredescribed in U.S. Pat. Nos. 4,917,089; 4,484,579; and 3,874,338; and WO91/01689.

Thoracoscopic and other minimally invasive heart valve repair andreplacement procedures are described in U.S. Pat. Nos. 5,855,614;5,829,447; 5,823,956; 5,797,960; 5,769,812; and 5,718,725.

BRIEF SUMMARY OF THE INVENTION

The present invention provides methods, devices, and systems for theendovascular repair of cardiac valves, particularly the atrioventricularvalves which inhibit back flow of blood from a heart ventricle duringcontraction (systole), most particularly the mitral valve between theleft atrium and the left ventricle. By “endovascular,” it is meant thatthe procedure(s) of the present invention are performed withinterventional tools and supporting catheters and other equipmentintroduced to the heart chambers from the patient's arterial or venousvasculature remote from the heart. The interventional tools and otherequipment may be introduced percutaneously, i.e., through an accesssheath, or may be introduced via a surgical cut down, and then advancedfrom the remote access site through the vasculature until they reach theheart. Thus, the procedures of the present invention will generally notrequire penetrations made directly through the exterior heart muscle,i.e., myocardium, although there may be some instances wherepenetrations will be made interior to the heart, e.g., through theinteratrial septum to provide for a desired access route. While theprocedures of the present invention will usually be percutaneous andintravascular, many of the tools will find use in minimally invasive andopen surgical procedures as well. In particular, the tools for capturingthe valve leaflets prior to attachment can find use in virtually anytype of procedure for modifying cardiac valve function.

The atrioventricular valves are located at the junctions of the atriaand their respective ventricles. The atrioventricular valve between theright atrium and the right ventricle has three valve leaflets (cusps)and is referred to as the tricuspid or right atrioventricular valve. Theatrioventricular valve between the left atrium and the left ventricle isa bicuspid valve having only two leaflets (cusps) and is generallyreferred to as the mitral valve. In both cases, the valve leaflets areconnected to the base of the atrial chamber in a region referred to asthe valve annulus, and the valve leaflets extend generally downwardlyfrom the annulus into the associated ventricle. In this way, the valveleaflets open during diastole when the heart atria fill with blood,allowing the blood to pass into the ventricle. During systole, however,the valve leaflets are pushed together and closed to prevent back flowof blood into the atria. The lower ends of the valve leaflets areconnected through tendon-like tissue structures called the chordae,which in turn are connected at their lower ends to the papillarymuscles. Interventions according to the present invention may bedirected at any one of the leaflets, chordae, annulus, or papillarymuscles, or combinations thereof. It will be the general purpose of suchinterventions to modify the manner in which the valve leaflets coapt orclose during systole so that back flow or regurgitation is minimized orprevented. While the procedures of the present invention will be mostuseful with the atrioventricular valves, at least some of the toolsdescribed hereinafter may be useful in the repair of other cardiacvalves, particularly the aortic valve.

The methods of the present invention will usually comprise accessing apatient's vasculature at a location remote from the heart, advancing aninterventional tool through the vasculature to a ventricle and/oratrium, and engaging the tool against a tissue structure which forms orsupports the atrioventricular valve. By engaging the tool against thetissue structure, the tissue structure is modified in a manner thatreduces valve leakage or regurgitation during ventricular systole. Thetissue structure may be any of one or more of the group consisting ofthe valve leaflets, chordae, the valve annulus, and the papillarymuscles. Optionally, the interventional tool will be oriented relativeto the atrioventricular valve and/or tissue structure prior to engagingthe tool against the tissue structure. The interventional tool may beself-orienting (e.g., pre-shaped) or may include active mechanisms tosteer, adjust, or otherwise position the tool. Alternatively,orientation of the interventional tool may be accomplished in whole orin part using a separate guide catheter, where the guide catheter may bepre-shaped and/or include active steering or other positioning means. Inall cases, it will usually be desirable to confirm the position prior toengaging the valve leaflets or other tissue structures. Such orientingstep may comprise positioning the tool relative to a line of coaptationin the atrioventricular valve, e.g., engaging positioning elements inthe valve commissures.

In a first aspect of the method of the present invention, the tissuestructure comprises the valve leaflets and the engaging step comprisesattaching one or more opposed points on or along the valve leafletstogether. In the case of the bicuspid mitral valve, the attachmentpoints may be located at or near the center of each leaflet, creating agenerally symmetric structure with two openings, i.e., between theattachment point(s) and each of the two commissures. Alternatively, theattachment points may be close to each of the commissures. Both willeffectively reduce the area in which the valve can open. In the case ofthe tricuspid valve, any two of the three leaflets can be partially ortotally closed together or all three may be partially closed together.

In both cases, the attachment of the valve leaflets may be performed ina variety of ways, including suturing, clipping, stapling, riveting,gluing, fusing, or the like. While each of these approaches may differsignificantly in the protocols and devices used for performing them, theend result will be the same, i.e., improved ability of theatrioventricular valve to close against the elevated pressures withinthe ventricle during systole. In order to improve apposition of thevalve leaflets, it may be preferred to attach the leaflets at a pointspaced inwardly from the free edge of the leaflet. Usually, theattachment point within the valve leaflet will be located from 1 mm to 4mm inward from the free edge.

It will frequently be desirable to stabilize the interventional toolrelative to the valve leaflets and other heart tissue structures atleast some points during the interventional procedure. In a broad sense,such stabilization is intended primarily to couple motion of theinterventional tool to the motion of the heart so that the tool may thenengage the valve leaflets or other target tissue structures with minimumdifferential motion. The stabilization may be achieved either throughthe interventional tool or through a guide catheter or other platformwhich is used to deliver the interventional tool. In both cases,stabilization will usually be achieved by engaging a tissue structure ofthe heart, such as the interatrial septum, the atrial wall, the valveannulus, the valve chordae, the papillary muscles, or the like. Forantegrade approaches, immobilization of either the guide catheter, theinterventional tool, or both relative to the valve annulus or valvecommissures will be particularly effective. For retrograde approaches,immobilization against the papillary muscles, the chordae, or the valveleaflets themselves may be particularly effective. Stabilization shouldbe distinguished from valve capture which is usually performed after theinterventional tool and/or guide catheter have been stabilized withinthe heart. Thus, the methods of the present invention may comprise up tofour separate steps or phases prior to valve affixation. First, theinterventional tool and/or guide catheter may be positioned, eitheractively or passively. Second, the interventional tool and/or guidecatheter may be stabilized within the heart. Next, the interventionaltool may be used to capture the valve leaflets. Then, prior toaffixation, the valve leaflets may be positioned and, if necessary,repositioned in order to determine that a particular coaptation andaffixation are capable of inhibiting the valve regurgitation. Finally,once adequate regurgitation inhibition has been confirmed, the valveleaflets may be affixed in any of the manners described below.

In a particular approach, the interventional tool may be stabilized bymechanically fixing the shape of the tool after the tool has beenadvanced to a position proximate the atrioventricular valve. Forexample, the interventional tool can comprise a plurality of linkedelements which can be locked into place, e.g., a “goose-neck” device.Such mechanically lockable devices may be used by themselves or inconjunction with any of the other stabilization devices describedherein.

When attaching portions of the valve leaflets together, it willfrequently be desirable to temporarily capture the valve leaflets beforeimplementing the final attachment step. For example, the leaflets can becaptured using forceps or other graspers introduced as part of orseparately from the interventional tool. After capturing the valveleaflets, flow through the valve can be observed by conventional cardiacimaging techniques, such as trans-esophegeal echocardiography (TEE),intracardiac echocardiography (ICE) or other ultrasonic imagingtechnique, fluoroscopy, angioscopy, catheter based magnetic resonanceimaging (MRI), computed tomography (CT) and the like. By thus observingthe flow through the valves, and more importantly whether or not backflow or regurgitation continues or has been sufficiently inhibited, thedesired attachment configuration for the leaflets can be determined. Ifcontinued regurgitation is observed, the valve leaflets may berepositioned and the presence or absence of regurgitation againdetermined. Such repositioning steps may be continued until a positionis identified in which the regurgitation is sufficiently inhibited.Additionally, other considerations, such as position of the attachmentwithin the leaflet, stress placed on the leaflet, and other factors canbe visualized before deciding on the final attachment point(s). In apreferred example, the valve leaflets may be coapted by a graspinginstrument which also has a fixation mechanism, such as stapling,suturing, clipping or riveting as previously described, so that once adesirable attachment configuration is temporarily achieved, the finalattachment can be made using the same instrument. Grasping of the valveleaflets can be accomplished using articulated graspers, vacuum-assistedgraspers, grasping pins, or other temporary attachment modes asdescribed in more detail below. After the leaflets are in the desiredconfiguration, they may be permanently secured together by any of thetechniques described above.

In a second aspect of the method of the present invention, the tissuestructure comprises the chordae and the engaging step comprises linkingopposed chordae together, i.e., chordae attached to different valveleaflets. Usually, the chordae will be partially gathered or coupledtogether using a suture or other loop structure. In some instances itmay be desirable to closely tie the chordae together at one or morelocations.

In a third aspect of the method of the present invention, the tissuestructure comprises the chordae and the engaging step comprises applyingenergy to shorten the chordae. Particular forms of heat energy, mostparticularly radiofrequency energy, have been found to be able to modifyand shrink collagen so that supporting chordae may be tightened. Byapplying energy to shorten one or more of the chordae attaching eitheror both (or all three in the case of the tricuspid valve) valveleaflets, the flow through the atrioventricular valve can be modifiedand regurgitation minimized. In a preferred aspect of the presentinvention, the chordae will be initially grasped or captured andmanipulated to temporarily apply tension to the valve leaflets. Theeffect of such temporary shortening can then be visually assessed and,if a desired improvement in valve performance is observed, energy can beapplied to shorten the chordae. In many cases, however, it may bepreferable to apply a clip, ring, suture loop, or other mechanicalelement to permanently twist, plicate, or otherwise shorten the chordae,as described elsewhere herein.

In a fourth aspect of the method of the present invention, the tissuestructure comprises the valve annulus and the engaging step comprisescircumferentially tightening or shortening the annulus. In a preferredtechnique, the annulus will be strengthened by positioning and attachinga supporting structure over the annulus in a manner broadly analogous tothe open surgical placement of an annuloplasty ring. Alternatively, theannulus can be tightened by surgical plication techniques, or in someinstances by shrinking tissue within the annulus by applyingradiofrequency energy as generally described above in connection withshortening of the chordae.

In a fifth aspect of the method of the present invention, the tissuestructure comprises the papillary muscles and the engaging stepcomprises capturing and drawing opposed points or portions of thepapillary muscles together. This approach is similar in many respects tocapture of the chordae, and will generally comprise suturing orotherwise forming a linkage between the opposed portions of thepapillary muscles. As with the chordae, it will generally not bedesirable to fully close the papillary muscles together, although insome instances such an approach may also find use.

In all the aspects of the method described above, the heart will usuallyremain beating while the interventional tool is engaged against thetissue structure. When the heart is beating, however, it may bedesirable to temporarily stop valve action during at least a portion ofthe procedure, particularly to facilitate grasping of the valve leafletswhen such a technique is being employed. The valve action can be slowedtemporarily by decreasing the heart rate with intravenous infusion of abeta blocker, such as esmolol, or can be completely stopped for a brieftime, e.g., five to ten seconds, by infusion of a drug, such asadenosine. Alternatively, the valve action can be stopped by temporarilyraising the pressure in the associated ventricle to a pressure abovethat in the atrium during diastole. While the heart will continue tobeat, the motion of the valve leaflets opening and closing will bestopped to facilitate grasping. As a further alternative, it will bepossible to mechanically restrain the leaflets directly or by capturingthe chordae, as described in more detail below. While such an approachmay be effective for some purposes, the difficulty in capturing thevalve leaflets initially may still be present.

While the methods of the present invention are particularly desirablesince they permit interventions to occur without stopping the heart,they may also be used with patients undergoing cardiopulmonary bypass.Such cardiopulmonary bypass can be achieved by any presently availabletechnique, including both conventional systems and recently developedendovascular bypass systems, such as those available from Heartport,Inc., Redwood City, Calif.

During the procedures performed while the heart is beating, it willoften be desirable to stabilize the interventional tool against one ormore cardiac structures prior to grasping the leaflets with theinterventional tool. Such stabilization will lessen the relative motionbetween the tool and the structure. Stabilization mechanisms may beseparate from or integral with any part of the system or device,including but not limited to guidewires, guiding catheters andinterventional tools. Likewise, the stabilization mechanisms may provideone or more additional functions in the tissue modification procedure,such as steering, orientation assessment, grasping, coaptation,adjustment and fixation. Therefore, many components in the system mayhave dual purposes.

Coaptation may be performed by a number of methods, such as capturingthe leaflets or by releasably capturing the chordae attached to eachleaflet. An exemplary capture device will comprise a snare, or a pair ofsnares, which are advanced through the chordae to capture or entangleindividual chordae. This snare or snares may then be tightened to drawthe chordae partially together and limit valve motion, at leastpartially. After such coaptation is achieved, the valve leaflets,chordae, papillary muscles, or annulus may then be engaged and modified,e.g., the leaflets may be attached, using a separate interventionaltool, as described above and elsewhere herein. Alternatively, it will bepossible to form a permanent link, bridge, or capture of the chordae ifthe temporary coaptation appears sufficient to repair valve function. Insome instances, it may be sufficient to simply detach the snare or othercapture mechanism and leave it in place permanently. In other instances,it will be possible to exchange the snare for a more permanentattachment structure, such as a suture loop or metallic coil. Forexample, once the snare is in place, if the valve function is acceptablyrepaired, the snare may be drawn out from the chordae through theplacement catheter, where the snare pulls a length of suture in themanner of a needle passing through tissue. The suture can then be tiedor otherwise fastened to form a permanent capture loop for the chordae.Alternatively, a separate attachment structure, such as a metal coil,barb, malecot, or the like, may be advanced around the snared chordae toeffect permanent capture, where a structure will be detached and left inplace.

The methods described above may be performed using either antegrade orretrograde endovascular access through the vasculature. The followingdescription will describe both antegrade and retrograde accessapproaches for gaining access to the mitral valve. Mitral valve accessis generally more difficult than tricuspid valve access. In a retrogradeapproach, the interventional tool, optional guiding catheter, and anyother supporting devices, will be introduced through distal arterialvasculature and over the aortic arch and into the left ventricle throughthe aortic valve. Typically, the aortic arch or via a brachial approachwill be approached through a conventional femoral artery access route,but could also be approached through the brachial artery, axillaryartery, or a carotid artery. When entering the left ventricle, theinterventional tool will generally be directed downwardly and away fromthe mitral valve structure. Thus, the interventional tool will usuallybe curved or turned so that it approaches the mitral valve from below,usually through the chordae toward the valve annulus. For example, theinterventional tool can enter the left ventricle through the aorticvalve and then be deflected or otherwise steered to turn 90° to directlyapproach the mitral valve and chordae. Steering of the tool can beaccomplished by deflecting a supporting catheter using pull wires,pre-formed curved catheters, or the like. In some instances, thepapillary muscles could be more directly accessed since they generallylie below the aortic valve and inline with the tool as it enters theleft ventricle.

Often, it will be desirable to position the interventional tool towardthe target tissue structure using a preformed and/or steerable guidecatheter. In a retrograde approach, the guide catheter may be placedfrom an access point, e.g., the femoral artery at the patient's groin,so that it passes over the aortic arch, through the aortic valve, andinto the left ventricle where it will form an access path to the targettissue structure. When the tissue structure is the chordae or valveleaflets, the guide catheter will usually have to be curved or beeverted or turned backward so that it can turn the interventional toolaround. Additionally, it may be desirable to provide for stabilizationof the distal end of the guide catheter. Stabilization may be providedby extendible elements, wires, cages, balloons, or other structureswhich engage the valve annulus, chordae or ventricular wall portions.Alternatively, two or more stabilizing extensions may be provided toproject forwardly from the guide catheter and seat in the valvecommissures to position and hold the guide catheter in place. Suchextendible elements may also be used to stabilize guidewires,interventional tools and other types of catheter systems. Specificstabilization structures will be described in more detail below.

Access for an antegrade endovascular approach will be through theinferior vena cava or superior vena cava into the right atrium. Suchantegrade access may, in itself, be sufficient to perform procedures onthe tricuspid valve from the top of the valve. Such procedures, however,will not be described in detail herein. To access the mitral valve, itwill be necessary to pass from the right atrium into the left atrium,typically by passing the tool through the interatrial septum. Theinteratrial septum may be endovascularly penetrated by conventionaltechniques, typically using a Brockenbrough needle, as described in thevalvuloplasty literature. Once the interatrial septum has beenpenetrated, the interventional tool may be passed into the left atriumso that it approaches the mitral valve from the top. Such an approachwill require that the access path turn downward, typically through anangle in the range from 0° to 120°.

The superior vena cava may be accessed through a variety of conventionalperipheral access sites, such as the internal jugular vein, while theinferior vena cava may be accessed through the femoral vein. Such accessmay be performed percutaneously or by surgical cut down techniques.

As with the retrograde arterial approach, the antegrade venous approachmay utilize placement of a guide catheter. With the use of a guidewire,the guide catheter will be configured to pass from the initial accesslocation, through either the superior vena cava or inferior vena cavainto the right atrium. The guide catheter will then be adapted to passthrough an interatrial penetration and into the left atrium, where itwill be pre-shaped or deflected to approach the mitral valve from thetop. The guidewire, guide catheter and/or the interventional catheterwhich carries the interventional tool may be steerable and mayoptionally have stabilizing elements. For example, in this specificembodiment, the guide catheter may have two or more laterally extensiblesteering wires and/or a plurality of stabilizing arms which projectforwardly and seat around the valve annulus or commissures to hold theguide catheter in place. The interventional tool may then be deployedthrough the guide catheter to perform the desired valve repairtechnique.

Systems according to the present invention comprise a guide catheterconfigured to pass from the remote vasculature of a patient to aposition within the heart adjacent to a target atrioventricular or othercardiac valve. The systems further comprise an interventional catheterconfigured to pass through the guide catheter and to engage theatrioventricular or other cardiac valve and/or associated cardiacstructures and an interventional tool on the interventional catheteradapted to modify the atrioventricular or other cardiac valve leaflets,valve annulus, valve chordae or papillary muscles to reduceregurgitation. In particular, the guide catheter can be configured foreither an antegrade or retrograde approach to the mitral valve, asdescribed above. The guide catheter may further comprise a stabilizingelement for engaging tissue within the heart to reduce relative movementbetween the guide catheter and the tissue while the heart remainsbeating. The structure can be any of the cages, wires, or the like,which have previously been described in connection with the method.Additionally, the interventional catheter may also comprise astabilizing element for engaging a tissue structure within the heart toreduce relative motion between the interventional catheter and thetissue. The stabilizing element can also be an expansible cage, steeringwires, or the like and may include vacuum and/or surface finishes toenhancing coupling. Specific interventional tools include suturingdevices, stapling devices, clip-applying devices, radiofrequencyelectrodes, surgical adhesive applicators, annuloplasty rings, and thelike.

Both the interventional tool and the guide catheter may employstabilizing mechanisms intended to engage a tissue structure within theheart to reduce relative movement between the interventional tool and/orguide catheter relative to the heart, and in particular relative to theatrioventricular valve. The stabilization mechanisms in both cases maybe the same. Typically, the stabilization mechanisms will be adapted toengage at least one tissue structure selected from the group consistingof the interatrial septum, the atrial wall, the valve annulus, the valvecommissures, the valve chordae, and the papillary muscles. For example,the stabilizing mechanism may comprise one or more extensible wireswhich are deployable radially outwardly to engage the tissue structure,such as the valve commissures. Alternatively, the stabilizing mechanismcould comprise an expansible cage that can be deployed to occupy all orat least a major portion of the atrium above the atrioventricular valve.As a still further alternative, the stabilizing mechanism could be apair of inflatable balloons which are spaced-apart and adapted to engagethe interatrial septum when the interventional tool and/or guidecatheter are passed therethrough.

In further specific aspects of the systems of the present invention, theinterventional tool may comprise a valve leaflet capture device intendedfor temporarily holding the valve leaflets prior to modification, e.g.,affixation. For example, the valve leaflet capture device may comprise apair of extensible elements which may be advanced from a distal end ofthe interventional tool to engage and capture the two mitral valveleaflets or three aortic valve leaflets. The particular capture toolsmay grasp the leaflets by pinching, partially or fully penetrating orpiercing, and/or suctioning the leaflets. The tools may comprise jaweddevices, looped devices, coiled devices or pronged devices, or vacuumdevices to grasp and hold the leaflets.

The present invention further provides methods for grasping anatrioventricular or other cardiac valve, particularly the mitral valve,to facilitate subsequent intervention or for other purposes. Thegrasping method comprises capturing chordae attached to at least oneleaflet of the valve while the heart is beating. Capture of the chordaefrom beneath the valve can modify leaflet movement and improve valvefunction, optionally closing portions of opposed valve leaflets againsteach other. Usually, chordae attached to valve leaflets (or possiblythree valve leaflets in the case of tricuspid valves) are capturedsimultaneously. For example, one or more snares, such as helical coils,can be advanced into the chordae to capture and immobilize portionsthereof. Alternatively, a loop element can be advanced through the valvechordae and tightened in order to modify valve function. In someinstances, capture of the chordae can be made permanent and will besufficient to treat the underlying regurgitation. In other cases,capture of the chordae will be primarily for leaflet coaptation, and theleaflets will be affixed by a subsequent interventional step.Preferably, the subsequent interventional step is performed while thechordae remain captured. The chordae can then be released after theleaflets or other tissue structures have been modified.

The present invention still further provides a chordae capture cathetercomprising a catheter body having a proximal end and a distal end. Meansare provided at or near the distal end of the catheter body forcapturing the chordae. A first exemplary means comprises one or morecoils which are extensible from the distal end of the catheter and whichengage and entangle the chordae when they are advanced therein. A secondexemplary capture means comprises a loop element which is extensiblefrom the distal end of the catheter and which is pre-formed to passthrough the chordae on one or both, preferably both valve leaflets inorder to draw the chordae together and modify valve function.

A further method according to the present invention for grasping anatrioventricular or other cardiac valve leaflets comprises capturing twovalve leaflets separately and preferably sequentially. Such capture iseffected by a leaflet capture catheter having at least three graspingjaws or prongs. A first valve leaflet is captured between a first pairof prongs, and second valve leaflet is captured between a second pair ofprongs. Optionally, the two prong pairs can have a common center prong,typically where the center prong is fixed (immobile) and the two outerprongs pivot in order to provide a pair of adjacent jaw-type graspers.By separately and sequentially grasping the two leaflets, the leafletscan be held in a preferred apposition and the improvement in valvefunction observed. Alternatively, the leaflets may be graspedsimultaneously. If the improvement is adequate, the valves can bepermanently affixed in a separate step. Optionally, the leaflet capturecatheter can include a device for fixing the valves, e.g., it can carrya clip which can be applied on to the valves as the capture catheter iswithdrawn.

The present invention still further provides leaflet capture catheterssuited for performing the method just described. The catheters comprisea catheter body having a proximal end and a distal end. A leafletgrasper is provided at or near the distal end of the catheter body andincludes at least three prongs wherein at least two of the three prongsare pivotable so that they may be separately actuated to separatelycapture individual leaflets or simultaneously actuated to capture theleaflets together. Optionally, the catheters further comprise means foraffixing the valve leaflets after they have been captured, preferablycomprising a clip-applier.

The present invention further includes leaflet capture catheters andtools which utilize a vacuum for grasping the valve leaflets andmanipulating the post leaflets into a desired apposition. Usually, thecatheter will have at least two vacuum channels at a distal end wherethe channels are preferably separately positionable and independentlyactuable. In that way, at least two valve leaflets can be separatelycaptured and positioned while the base catheter remains stationary. Thecatheter may be positioned in an antegrade or retrograde manner with thetool entering between the valve leaflets and optionally between thechordae. The tool and/or catheter may optionally further includemodification devices, such as suture appliers, clip appliers, staplers,rivet appliers, adhesive applicators, heating elements for shorteningthe chordae, and others of the specific interventional tools describedhereinafter. Likewise, the present invention further includes cathetersand tools which include lumens for monitoring pressures within thechambers of the heart, and/or infusion of radiopaque contrast solution.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of the left ventricle of a heartshowing blood flow during systole with arrows.

FIG. 2 is a schematic illustration of the left ventricle of a hearthaving prolapsed leaflets in the mitral valve.

FIG. 3 is a schematic illustration of a heart in a patient sufferingfrom cardiomyopathy where the heart is dilated and the leaflets do notmeet.

FIG. 3A shows normal closure of the leaflets, while FIG. 3B showsabnormal closure in the dilated heart.

FIG. 4 illustrates mitral valve regurgitation in the left ventricle of aheart having impaired papillary muscles.

FIG. 5 is a schematic illustration showing direct attachment of opposedvalve leaflets to reduce valve regurgitation according to the methods ofthe present invention.

FIG. 6 is a schematic illustration showing attachment of valve chordaeto treat valve regurgitation according to the methods of the presentinvention.

FIGS. 7-8 show exemplary antegrade approaches to the mitral valve fromthe venous vasculature.

FIGS. 9-10 show exemplary retrograde approaches to the mitral valvethrough the aortic valve and arterial vasculature.

FIGS. 11-14 illustrate the use of adjustment wires for steeringcapability.

FIGS. 15A-15D illustrate the use of pre-shaped mandrels to steer acomponent or structure.

FIGS. 16-20, 21A-21C, and 22A-22B depict various orientation assessmenttools.

FIG. 23 is a schematic illustration of an interatrial septumstabilization device.

FIG. 24 is a schematic illustration of a catheter shaft designed toprovide stabilization against a structure, such as the interatrialseptum, or for flexible adjustment and locking stability in variouspositions.

FIG. 25 is a schematic illustration of an atrial stabilization device.

FIGS. 26-29 illustrate stabilization mechanisms which utilize couplingto the valve annulus.

FIGS. 30, and 31A-31D illustrate stabilization mechanisms which utilizecoupling with the valve commissures and/or leaflets.

FIGS. 32A and 32B illustrate mitral valve stabilization using snares forcapturing the valve chordae.

FIGS. 33A and 33B illustrate an antegrade approach for snaring valvechordae and optionally suturing the chordae together to treat valveregurgitation.

FIG. 34 illustrates an antegrade approach for snaring valve chordae tostabilize the mitral valve.

FIGS. 35 and 35A illustrate a snaring catheter particularly intended forcapturing valve chordae from a retrograde approach.

FIGS. 36A and 36B illustrate use of the catheter FIG. 35 for snaringvalve chordae.

FIGS. 37 and 38 illustrate a catheter similar to that shown in FIGS. 35and 35A, except that it includes a working channel for introducinginterventional catheters and tools to treat the mitral or otheratrioventricular valve according to the methods of the presentinvention.

FIGS. 39A and 39B illustrate a coil which can be implanted within thevalve chordae to stabilize the mitral valve.

FIG. 40 illustrates placement of the coil of FIGS. 39A and 39B from aretrograde approach.

FIGS. 41A-41B, 42A-42B and 43 illustrate valve leaflet grasping deviceswhich utilizes a pinching method.

FIGS. 44A-44D are schematic illustrations of an atrial-ventricular valveleaflet grasping device which utilizes a pinching method.

FIGS. 45A-45B are schematic illustrations of a grasping device whichutilizes rollers in a pinching method.

FIGS. 46A-46B are schematic illustrations of a grasping device whichutilizes a pair of opposing coils in a pinching method.

FIGS. 47A-D illustrate a pronged valve leaflet device which utilizes apinching, partially penetrating or piercing method.

FIG. 48 illustrates a vacuum-assisted stabilization catheter for use inthe methods of the present invention.

FIG. 49 illustrates an embodiment of a valve suturing device accordingto the present invention.

FIGS. 49A-49C illustrate an additional embodiment of a valve suturingdevice according to the present invention.

FIG. 50 illustrates a further embodiment of a valve suturing deviceaccording to the present invention.

FIG. 51 illustrates use of the catheter for capturing and suturingopposed mitral valve leaflets.

FIG. 52 illustrates the mitral valve leaflets which have been secured asshown in FIG. 51.

FIGS. 53 and 54 illustrate an alternative anchor which can be used withthe suturing devices of the present invention.

FIGS. 55A-55B illustrate the use of an expansible anchor in fixation.

FIGS. 56 and 57 illustrate yet another suturing device according to thepresent invention.

FIG. 58 illustrates use of the suturing device of FIGS. 56 and 57 toplace sutures between valve leaflets of the mitral valve.

FIG. 59 illustrates yet another embodiment of a suturing deviceaccording to the present invention.

FIG. 60 illustrates use of the device of FIG. 59 and suturing opposedmitral valve leaflets.

FIGS. 61A and 61B illustrate a stapling device which can be used tostaple opposed leaflets of an atrioventricular valve according to themethods of the present invention.

FIGS. 62A-D are schematic illustrations of fixation devices.

FIG. 63 illustrates an alternative two part fixation stapling device.

FIG. 64 illustrates use of the stapling device of FIG. 63 for staplingopposed valve leaflets of a mitral valve.

FIG. 65A-65C are schematic illustrations of coiled fixation devices.

FIG. 66 illustrates use of a self-securing anchor for attaching opposedsurfaces on the leaflets of the mitral valve.

FIGS. 66A-66B are schematic illustrations of penetrating fixationdevices.

FIGS. 67 and 68 are schematic illustrations of penetrating fixationdevices with barb-like distal ends.

FIGS. 69A-C and 70A-B are schematic illustrations of clips used asfixation devices.

FIGS. 71, and 72A-72B are schematic illustrations of clips involving theuse of graspers in the fixation mechanism.

FIGS. 73A-73C illustrate a three-jaw clip-applier.

FIG. 74 illustrates a clip which has been applied by the clip-applier ofFIGS. 73A-73C.

FIG. 75 illustrates a device for applying radiofrequency energy toshorten valve chordae.

FIGS. 76, and 77A-77B illustrates devices used to plicate and shortenvalve chordae.

FIG. 78 illustrates a first exemplary approach for placing anannuloplasty ring according to the methods of the present invention.

FIGS. 79 and 80 illustrate a second exemplary approach for placing anannuloplasty ring according to the methods of the present invention.

FIG. 81 illustrates a method for placing an anchored filament about amitral valve annulus that can be used to tighten the annulus.

FIG. 82 illustrates a method for placing multiple sutures about a mitralvalve annulus, where the individual suture plicate and tighten theannulus.

FIGS. 83-85 illustrate an embodiment of an atrial device for valvetissue modification.

FIGS. 86, and 87A-87C illustrate an embodiment of an atrial-ventriculardevice for valve tissue modification.

FIGS. 88-89, and FIGS. 90A-90B illustrate an embodiment of a ventriculardevice for valve tissue modification.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

I. Cardiac Physiology

The left ventricle LV of a normal heart H in systole is illustrated inFIG. 1. The left ventricle LV is contracting and blood flows outwardlythrough the tricuspid (aortic) valve AV in the direction of the arrows.Back flow of blood or “regurgitation” through the mitral valve MV isprevented since the mitral valve is configured as a “check valve” whichprevents back flow when pressure in the left ventricle is higher thanthat in the left atrium LA. The mitral valve MV comprises a pair ofleaflets having free edges FE which meet evenly to close, as illustratedin FIG. 1. The opposite ends of the leaflets LF are attached to thesurrounding heart structure along an annular region referred to as theannulus AN. The free edges FE of the leaflets LF are secured to thelower portions of the left ventricle LV through chordae tendineae CT(referred to hereinafter as the chordae) which include plurality ofbranching tendons secured over the lower surfaces of each of the valveleaflets LF. The chordae CT in turn, are attached to the papillarymuscles PM which extend upwardly from the lower portions of the leftventricle and interventricular septum IVS.

Referring now to FIGS. 2-4, a number of structural defects in the heartcan cause mitral valve regurgitation. Ruptured chordae RCT, as shown inFIG. 2, can cause a valve leaflet LF2 to prolapse since inadequatetension is transmitted to the leaflet via the chordae. While the otherleaflet LF1 maintains a normal profile, the two valve leaflets do notproperly meet and leakage from the left ventricle LV into the leftatrium LA will occur, as shown by the arrow.

Regurgitation also occurs in the patients suffering from cardiomyopathywhere the heart is dilated and the increased size prevents the valveleaflets LF from meeting properly, as shown in FIG. 3. The enlargementof the heart causes the mitral annulus to become enlarged, making itimpossible for the free edges FE to meet during systole. The free edgesof the anterior and posterior leaflets normally meet along a line ofcoaptation C as shown in FIG. 3A, but a significant gap G can be left inpatients suffering from cardiomyopathy, as shown in FIG. 3B.

Mitral valve regurgitation can also occur in patients who have sufferedischemic heart disease where the functioning of the papillary muscles PMis impaired, as illustrated in FIG. 4. As the left ventricle LVcontracts during systole, the papillary muscles PM do not contractsufficiently to effect proper closure. The leaflets LF1 and LF2 thenprolapse, as illustrated. Leakage again occurs from the left ventricleLV to the left atrium LA, as shown by the arrow.

II. Interventional Approaches

The present invention treats cardiac valve regurgitation, particularlymitral valve regurgitation, by intervention at either of two locations.First, as shown in FIG. 5, the valve leaflets LF may be directlyattached or coupled to each other by a structure S or other means.Typical structures include suture, staples, clips, pins, or otherclosure devices of a type commonly used in attaching opposed tissuesurfaces. Alternatively, the opposed surfaces on the valve leafletscould be attached using adhesives, fusion energy, includingradiofrequency current, laser energy, microwave, ultrasonic energy, orthe like. A variety of specific techniques for valve leaflet attachmentwill be described hereinafter.

A second and often preferred interventional point will be in thechordae, as shown in FIG. 6. There, an attachment structure S is shownto couple individual chordae or tendons which are attached to each ofthe two leaflets LF. A variety of specific structures can be utilized,such as snares, staples, sutures, coils, clips, snaps, rivets,adhesives, and the like. Opposed chordae will usually also be attacheddirectly, optionally employing any of the same structures listed above.Alternatively, opposed chordae may be indirectly tied or coupledtogether by a structure which links or couples their movement, but whichdoes not physically attach chordae from each of the valve leafletsdirectly together. In addition to attaching the chordae, chordalintervention can include shortening the chordae, e.g., by applyingenergy to shrink the collagen therein, or may utilize mechanicalplication devices, such as clips, to physically shorten the chordae.

III. Access to the Mitral Valve

Access to the mitral valve or other atrioventricular valve willpreferably be accomplished through the patient's vasculature in a“percutaneous” manner. By “percutaneous” it is meant that a location ofthe vasculature remote from the heart is accessed through the skin,typically using a surgical cut down procedure or a minimally invasiveprocedure, such as using needle access through, for example, theSeldinger technique. The ability to percutaneously access the remotevasculature is well-known and described in the patent and medicalliterature. Depending on the point of vascular access, the approach tothe mitral valve may be “antegrade” and require entry into the leftatrium by crossing the interatrial septum. Alternatively, approach tothe mitral valve can be “retrograde” where the left ventricle is enteredthrough the aortic valve. Once percutaneous access is achieved, theinterventional tools and supporting catheter(s) will be advanced to theheart intravascularly where they may be positioned adjacent the targetcardiac valve in a variety of manners, as described elsewhere herein.While the methods will preferably be percutaneous and intravascular,many of the tools described herein will, of course, also be useful forperforming open surgical techniques where the heart is stopped and theheart valve accessed through the myocardial tissue. Many of the toolswill also find use in minimally invasive procedures where access isachieved thorascopically and where the heart will usually be stopped butin some instances could remain beating.

A typical antegrade approach to the mitral valve is depicted in FIGS. 7and 8. The mitral valve MV may be accessed by an approach from theinferior vena cava IVC or superior vena cava SVC, through the rightatrium RA, across the interatrial septum IAS and into the left atrium LAabove the mitral valve MV. As shown in FIG. 7, a catheter 10 having aneedle 12 may be advanced from the inferior vena cava IVC into the rightatrium RA. Once the catheter 10 reaches the anterior side of theinteratrial septum IAS, the needle 12 may be advanced so that itpenetrates through the septum at the fossa ovalis FO or the foramenovale into the left atrium LA. At this point, a guidewire may beexchanged for the needle 12 and the catheter 10 withdrawn.

As shown in FIG. 8, access through the interatrial septum IAS willusually be maintained by the placement of a guide catheter 14, typicallyover a guidewire 16 which has been placed as described above. The guidecatheter 14 affords subsequent access to permit introduction of theinterventional tool(s) which will be used for performing the valve ortissue modification, as described in more detail below.

The antegrade approach to the mitral valve, as just described, isadvantageous in a number of respects. For example, the use of theantegrade approach will usually allow for more precise and effectivecentering and stabilization of the guide catheter and/or interventionaltool. Precise positioning, of course, facilitates accuracy in the tissuemodification, particularly affixation of the valve leaflets or chordae.The antegrade approach also reduces the risk of damaging the subvalvularapparatus during catheter and interventional tool introduction andmanipulation. Additionally, the antegrade approach eliminates the risksassociated with crossing the aortic valve. This is particularly relevantto patients with prosthetic aortic valves which cannot be crossed. Whenemploying chordal fixation, the tools can be placed very close to thefree edge of the leaflet since they will be removed in a direction awayfrom the chordae which are being fixed. Additionally, an antegradeapproach allows more direct access to the valve leaflets unimpeded bypresence of the chordae.

A typical retrograde approach to the mitral valve is depicted in FIG. 9.Here the mitral valve MV may be accessed by an approach from the aorticarch AA, across the aortic valve AV, and into the left ventricle belowthe mitral valve MV. The aortic arch AA may be accessed through aconventional femoral artery access route, as well as through more directapproaches via the brachial artery, axillary artery, or a radial orcarotid artery. Such access may be achieved with the use of a guidewire42. Once in place, a guide catheter 40 may be tracked over the guidewire42. The guide catheter 40 affords subsequent access to permitintroduction of the interventional tool(s) which will be used forperforming the valve or tissue modification, as described in more detailbelow.

In some instances, a retrograde arterial approach to the mitral valvewill be preferred due to its advantages. Use of the retrograde approachwill eliminate the need for a trans-septal puncture. The retrogradeapproach is also more commonly used by cardiologists and thus has theadvantage of familiarity. Additionally, the retrograde approach providesmore direct access to the chordae.

The interventional tool(s) used for performing the valve or tissuemodifications may be specifically designed for the approach or they maybe interchangeable. For example, tools may be specifically designed foran antegrade or retrograde approach, or they may be designed to be usedwith either approach. In any case, tools may be used in any appropriatefashion to achieve a desired result. However, for the sake of clarity, anomenclature has been developed to describe the common usage of suchtools. Tools which perform the modification procedure while primarilyresiding primarily in the atrium are referred to as “atrial” tools.These utilize an antegrade approach. Tools which perform themodification procedure while primarily residing in the ventricle arereferred to as “ventricular” tools, and likewise utilize a retrogradeapproach. Tools which cross over the valve to perform the modificationprocedure, residing in both the atrium and the ventricle, are referredto as “atrial-ventricular” tools, and may utilize either an antegrade orretrograde approach.

IV. Orientation Steering

Approaching the desired valve or tissue structure for effectivetreatment, as described above, requires proper orientation of thecatheters, tools and devices used throughout the procedure. Suchorientation may be accomplished by gross steering of the device to thedesired location and then refined steering of the device components toachieve a desired result.

Gross steering may be accomplished by a number of methods. First, asteerable guidewire may be used to introduce a guide catheter,interventional tool and/or treatment device into the proper position.The guide catheter may be introduced, for example, using a surgical cutdown or Seldinger access to the femoral artery in the patient's groin.After placing a guidewire, the guide catheter may be introduced over theguidewire to the desired position. Alternatively, a shorter anddifferently shaped guide catheter could be introduced through the otherroutes described above.

Second, a guide catheter may be pre-shaped to provide a desiredorientation relative to the mitral valve. For example, as shown in FIGS.9 and 10, guide catheter 40 may have a pre-shaped J-tip which isconfigured so that it turns toward the mitral valve MV after it isplaced over the aortic arch AA and through the aortic valve AV. As shownin FIG. 9, the guide catheter 40 may be configured to extend down intothe left ventricle LV and to evert so that the orientation of aninterventional tool or catheter is more closely aligned with the axis ofthe mitral valve MV. The guide catheter 40 of FIG. 10 orients aninterventional catheter (not shown) in a lateral direction relative tothe access of the mitral valve MV. Each of the guide catheters 40 shownin FIGS. 9 and 10 may find use under different circumstances. Forexample, the guide catheter 40 of FIG. 10 might be particularly suitedfor introducing tools which modify the chordae CT, while the catheter 40of FIG. 9 may be more useful for engaging tools against the valveleaflets. As shown in FIG. 9, a guidewire 42 may be positioned from thetip of the guide catheter 40 directly through the opening of the mitralvalve MV. Interventional tools can then be directed over the guidewire42 to form the particular procedures described hereinafter. Likewise,the interventional tool itself may be pre-shaped to provide a desiredorientation.

Third, the guidewire, guide catheter or interventional tool may beactively deflected, e.g., having push/pull wires which permit selectivedeflection of the distal end in 1, 2, 3, or 4 directions depending onthe number of pull wires, having shape memory nitinol, or havingballoons, wires, wire cages or similar mesh structures to direct thedevice away from a cardiac structure and therefore into a desiredposition, to name a few.

Either of the guide catheters 40 shown in FIGS. 9 or 10 may be providedwith steering capabilities. For example, two or more adjustment wires 46may be provided at the distal tip of the guide catheter 40 as shown inFIG. 11. These adjustment wires may be active or passive, and may bepositioned within the valve commissures to enhance alignment of theguide catheter with the mitral valve MV. As shown in FIGS. 12A and 12B,the adjustment wires 46 may be positioned in the medial commissure MVCand lateral commissure LVC, and the guide catheter 40 may thus be movedfrom a central location, as shown in FIG. 12A to a more medial position,as shown in FIG. 12B. The catheter could of course also be moved in thelateral direction (not shown). The ability to position the guidecatheter will be of great benefit in performing the specificinterventions and valve modifications described hereinafter. It will beappreciated that similar steering mechanisms could be provided on aninterventional catheter introduced through the guide catheter, and insome instances it may be most desirable to provide the guidewire, theguide catheter, and the interventional catheter with steering andpositioning capabilities.

Steering wires 50 on a guide catheter 40 may also be provided to engageopposed surfaces within the left ventricle LV, as shown in FIG. 13. Byproviding such a steering capability, the distal tip of the guidecatheter 40 can be moved further downward from the mitral valve.Catheter 40 of FIG. 13 would be particularly useful in combination withan interventional catheter which itself has steering capabilities whichengage portions of the mitral valve, such as the valve commissures asdescribed above.

As shown in FIG. 14, the guidewire 52 may have laterally deflectablesteering elements 54 which may be positioned in, for example, the valvecommissures as described previously. This way, the guidewire 52 may bepositioned toward the medial or lateral sides of the mitral valve MV,and an interventional catheter 56 introduced over the guidewire to adesired target structure within or surrounding the mitral valve MV.Providing such a steerable and positionable guidewire, it isparticularly advantageous when it is desired to position the tip of aninterventional catheter 56 at a region well below the opening of themitral valve. That is, neither the guide catheter nor the interventionalcatheter have to be advanced fully to the opening of the mitral valve,leaving them free to be positioned elsewhere.

In some instances, it will be desirable to introduce interventionaltools sequentially or simultaneously from both the antegrade andretrograde directions. While it will be possible to separately introduceguiding catheters and guidewires by the approaches described above, inat least some instances it may be preferable to pass a single guidewirebetween the vena cava and the right atrium, crossing the interatrialseptum as previously described. The guidewire may then pass in anantegrade direction through the aortic valve, through the ascending anddescending aorta, and then percutaneously out of the vasculature at alocation remote from the heart, such as the femoral artery.

Location of a single guidewire in this manner provides a continuous“rail” through the heart, allowing placement of separate devices in bothan antegrade and retrograde direction. Additionally, any interaction orcooperation between the devices is facilitated since they willnecessarily advance toward one another in an alignment which iscontrolled and assured by the guidewire, e.g., when fully advanced anytwo devices will necessarily meet. Thus, one device would extend inwardfrom the venous side of the heart in an anterior antegrade direction tothe mitral valve, and a second device would enter through the arterialside of the heart in a retrograde direction. The two devices would thenbe precisely located relative to each other as they approach andoptionally meet at or near the mitral valve. In a particular example, astabilizing catheter could be introduced in a retrograde direction toapproach the chordae and underside of the mitral valve leaflets toprovide for temporary stabilization and/or leaflet coaptation, asgenerally described above. A catheter carrying a fixation device couldthen be advanced in an antegrade direction to approach the valveleaflets from above. The second device could then be separately actuatedto affix the valve leaflets once the proper temporary stabilization hasbeen achieved with the first device.

Fourth, the guidewire, guide catheter or interventional tool may bepositioned with the use of a floating balloon. This may be most usefulfor use with an antegrade approach. The distal balloon of a balloontipped guidewire or balloon tipped floppy catheter may be inflated andfloated antegrade through the mitral valve. If the heart is slowlybeating, blood will be flowing from the left atrium, through the mitralvalve to the left ventricle. A floating balloon may be carried alongthis flow trajectory, carrying the guidewire or catheter with it. Theballoon may then be deflated and newly placed guidewire or catheter maybe utilized as desired.

Fifth, a hollow guidewire, guide catheter or interventional or othertool may be positioned with the use of a rigid, pre-shaped mandrel orinsertable member. As shown in FIGS. 15A-D, the mandrel 600 may becomprised of wire, metal, plastic or any suitable material that may beformed to hold a desired shape 601, such as a bend or bump. The mandrel600 may then be inserted into a lumen in a flexible structure 602 to bepositioned. Such a structure may be a hollow guidewire, guide catheter,interventional tool or any other tool or component of a structure. Asthe shape 601 is advanced, the flexible structure 602 conforms to theshape 601 as it is passed through. This may be utilized to position astructure or component of a structure in a desired location for latersteps in the procedure.

It may be appreciated that any of the devices, systems and methods usedfor gross steering may be also be applied to refined steering of thedevice or device components to achieve a desired result. In particular,it may be desired to independently or dependently manipulate componentsof the interventional tools throughout the procedure. Such steering mayallow urging of the components relative to the leaflets, annulus, atrialwall or other specific cardiac structures. This may be achieved with anyof the devices or methods described above.

V. Orientation Assessment

Proper orientation of the systems and devices is necessary forperforming the valve or tissue modification. Both the orientation of thedevices and the components of the devices, in relation to cardiacstructures and to each other, are of concern. Cardiac structures towhich orientation is desired may include the atrial walls, interatrialseptum, valve annulus, valve leaflets, valve commissures, valve chordae,papillary muscles and ventricle walls, to name a few. Assessment of theorientation of the components and devices may be achieved by a number ofmechanisms and methodologies.

First, orientation may be assessed by tactile feedback. Introduction andmanipulation of the devices and components may allow them to contactcardiac structures or other devices. Such contact may guide the devicesinto proper position and relevant orientation. For example, it may bepossible to tactilely sense the force of the distal end of a guidewire,catheter or interventional tool against the leaflets, commissures,annulus, chordae, papillary muscles, ventricular walls, and/or atrialwalls, to name a few. The force may be translated along its length toits proximal end to provide feedback to the physician or operator.Similarly, sensors may be used to achieve a similar result.Additionally, the catheter or tool may have a lumen to allow forpressure monitoring. This may provide feedback throughout the procedurewhich may indicate the presence and level of mitral regurgitation.

Second, orientation may be assessed by visualization of the devices andcomponents themselves. The components or the overall system may bemodified for enhanced echogenic and/or fluoroscopic visibility.Echogenicity of a material in a blood medium is dependent on thedifference in acoustic impedance (product of velocity of sound anddensity of the medium through which the sound wave is traveling) betweenthe material and blood. Therefore, a thin polymer coating on thecomponents or the overall system may provide modulation of the acousticimpedance at the interface of the component and blood, thereby improvingechovisibility. Likewise, microscopic air bubbles trapped on the surfaceor embedded within the coating may also improve echovisibility.Similarly, fluoroscopic visibility may be improved with radiopaquecoatings, radiopaque marker bands, or the like. Additionally, a lumenwithin the catheter or tool may be provided to inject radiopaquecontrast solution to improve fluoroscopic visibility or surroundingtissues. In any case, such coatings, markings and fluids may providevisualization of the devices and components themselves or any structuresor elements used throughout the treatment procedure. Similarly,angioscopic vision may be used to access the orientation throughout theprocedure.

Third, one or more orientation elements may be used to assessorientation of the components and/or systems in relation to cardiacstructures, specifically the target valve. Thus, orientation elementsmay be any structure or feature that provides information as to theorientation of the component, device or system of the present invention.The elements may be separate from or integral with any part of thesystem or device. They may be removably or fixedly mounted on theguidewire, guide catheter, interventional tool and/or other device.Likewise, the elements may be components or parts of components of thedevice which provide one or more additional functions in the tissuemodification procedure, such as stabilization, grasping, coaptation,adjustment or fixation. Further the elements may be atrial, ventricularor atrial-ventricular devices such that they may or may not cross thevalve in the orientation assessment process. In addition, such elementsmay be used to steer and/or orient the components and systems prior toor simultaneous with assessment.

Orientation elements may be in the form of propellers, wings, petals,arms, loops, and the like. One or more of these elements may be present,typically extending radially from a central shaft. When two elements arepresent, they are commonly placed 120 to 180 degrees apart around thecentral shaft; more than two elements are typically arranged in a radialpattern around the central shaft. In the preferred embodiments, theorientation elements are typically placed either perpendicular to theline of coaptation or following the line of coaptation. This may providethe most useful reference, however many other placement orientations maybe used.

Examples of orientation elements placed perpendicular to the line ofcoaptation are depicted in FIGS. 16 and 17. FIG. 16 is a short axis viewof the mitral valve MV with an orientation element 612 shown having apair of orientation structures 613 arranged 180 degrees apart around acentral shaft 614. The orientation element 612 is shown perpendicular tothe line of coaptation C. Such positioning of the element 612 mayindicate that the device is in its desired orientation, specificcomponents are in a desired orientation, or devices or components may beoriented in relation to the positioned element which may be more visiblethan other parts of the device.

FIG. 17 is a long axis view of the mitral valve MV. Here, a guidewire615 with a pair of orientation propellers 616 is shown inserted throughthe mitral valve MV via a retrograde approach. Visualization of thepropellers 616 may allow repositioning of the guidewire 615 until thepropellers are perpendicular to the line of coaptation C. At this point,a guide catheter, interventional or other tool may be tracked over thecatheter in the desired orientation. Such tracking may be facilitatedwith the use of a keyed, notched, oval or similar lumen for guidance.Similarly, such orientation propellers 616 may be mounted on a guidecatheter with a keyed lumen for guided insertion of interventionaltools.

Examples of orientation elements placed along the line of coaptation aredepicted in FIGS. 18 and 19. FIG. 18 is a long axis view of anorientation element 620 inserted into the valve opening along the lineof coaptation C. An end view shown in FIG. 19 illustrates thepenetration of the element 620 through the valve opening and the valveleaflets LF sealing against the element 620. In addition, portions ofthe orientation element 620 may contact the commissures CM at each endof the valve opening for support and/or for reference. Using theposition of the orientation element 620 as a reference, the location ofa variety of cardiac structures, particularly the valve leaflets LF, areknown. In addition, if the position of specific components of the deviceare known in relation to the orientation elements 620, such relation maybe used to infer the relation of those components to the cardiacstructures. For example, if the orientation elements are known to beperpendicular to the graspers of the present invention, positioning ofthe orientation elements in the manner described above would ensure thatthe graspers would be aligned perpendicular to the line of coaptation Cor in a desirable location to grasp the valve leaflets LF.

In this example, the orientation element 620 is shown as an inflatablebladder coaxially attached to a distal central shaft 621. Such a bladdermay be comprised of a compliant or noncompliant material, such as PET,PUR, Silicone, Chronoprene, or the like. The bladder material itself maybe echo or fluorogenic, or it may be filled with an echo or fluorogenicliquid or suitable medium, such as carbon dioxide or agitated saline. Inits inflated state, it is preferred that the bladder is wide or thickenough to so that the endview of the bladder is visible in a short axisview of the mitral valve, as shown in FIG. 19, and that the bladder islong or high enough so that the anterior and posterior leaflets may sealagainst the bladder in systole.

In addition, as shown in FIG. 20, the bladder 625 may be supported by aframe 626. The frame 626 may be comprised of any suitable material, suchas nitinol, stainless steel, plastic or any combination thereof, of anyconsistent or variable flexibility, and any cross-sectional shape, suchas round wire, hollow tube or flat ribbon. This material may be echo orfluorogenic or treated for such effects. In addition, the shape of theframe 626 may be of any suitable symmetrical or nonsymmetrical geometry,including but not limited to triangular, rectangular, circular, oblong,and single or multi-humped. A rectangular geometry is depicted in FIG.20. In addition, the frame 626 may be expandable as shown in FIGS.21A-C. In the collapsed state, FIG. 21A, the bladder 625 and enclosedframe 626 may be inserted through a lumen in a guide catheter orinterventional tool. When appropriately positioned, the frame 626 may begradually expanded, FIG. 21B, to a desired geometry, FIG. 21C. It may beappreciated that the orientation element may function without inflationof the bladder 625 or with just the frame 625 and no bladder.

Fourth, orientation may be assessed by visualization of flow patternsresulting from system or component position with respect to cardiacstructures. As mentioned, the heart may be slowly beating throughout thetissue modification procedure. As the heart beats, blood may be flowingfrom the left atrium, through the mitral valve, to the left ventricle.Visualization of these flow patterns using Color DopplerEchocardiography may allow inferences as to how systems or componentsare positioned. For example, as shown in FIGS. 22A, if a thin planarstructure 650 is inserted in the valve opening with its long axisperpendicular to the line of coaptation C, a higher level ofregurgitation may result due to blood flow through the unsealed portions651. If the structure 650 is inserted with its long axis along the lineof coaptation C, as shown in FIG. 22B, a lower level of regurgitationmay result due to more adequate sealing of the valve leaflets LF againstthe structure 650. Thus, such a structure 650 or similarly designeddevice may be used as an orientation element.

VI. Stabilization

Before a valve or tissue modification or intervention is performed, itwill usually be desirable to temporarily stabilize the interventionaltool in relation to the a cardiac structure. By “stabilization” it ismeant that the interventional tool will be somehow coupled to a cardiacstructure so that any existing relative motion between the tool and thestructure is lessened. Cardiac structures which may be utilized forcoupling include the atrial walls, interatrial septum, valve annulus,valve leaflets, valve commissures, valve chordae, papillary muscles andventricle walls, to name a few. Such stabilization is performed in orderto facilitate a subsequent intervention. For example, an access cathetermay be mechanically coupled to the valve or tissue surrounding thevalve, such as the annulus or the chordae, and the interventional tooldeployed from the catheter to perform a desired intervention, such assuturing, stapling, snaring, annuloplasty, RF tissue modification, orthe like. The stabilization will usually be terminated after theparticular valve modification is completed, but in some instances thestabilization could be terminated and redeployed multiple times atvarious points throughout the procedure.

The stabilization mechanisms may be separate from or integral with anypart of the system or device. They may be removably or fixedly mountedon the guidewire, guide catheter, interventional tool and/or otherdevice. Likewise, the elements may be components or parts of componentsof the device which provide one or more additional functions in thetissue modification procedure, such as steering, orientation assessment,grasping, coaptation, adjustment or fixation. Further the mechanisms maybe atrial, ventricular or atrial-ventricular devices such that they mayor may not cross the valve in the stabilization process. In particular,such mechanisms may be used to steer and/or orient the components andsystems prior to or simultaneous with stabilization.

In the preferred embodiments, three general categories of stabilizationmechanisms may be formed for descriptive purposes: 1) stabilizationagainst the atrial septum, atrial walls or ventricle walls, 2)stabilization against the valve, and 3) stabilization against thechordae or papillary muscles. Stabilization against the atrial septummay be useful when approaching antegrade with atrial oratrial-ventricular devices. As previously described, an antegradeapproach involves crossing from the right atrium RA to the left atriumLA by penetrating the interatrial septum IAS. This may be accomplishedwith a needle bearing catheter, which may then be exchanged for anintroducer, guide catheter or similar catheter. Interventional tools maybe introduced through this catheter for tissue modification treatment.To prevent movement of the catheter in an axial direction, astabilization mechanism may be used to engage and lock the catheter tothe interatrial septum. A preferred embodiment is shown in FIG. 23,which depicts a catheter shaft 660 having a distal balloon 661 and aproximal balloon 662 inflated on opposite sides of the interarterialseptum IAS. Inflation of the balloons 661, 662 against the septumcouples the shaft 660 to the septum and stabilizes the system. It may beappreciated that a number of components, such as disks, cages, balls,mesh, or other structures, may be used in place of one or more of theballoons to achieve a similar result.

Stabilization against the atrial septum may also be achieved by formingan introducer or guide catheter which is rigid through the interatrialseptum and left atrium. Typically, such introducers or guide cathetersare flexible along their length to facilitate introduction through thetortuous paths of the vascular system. In an antegrade approach asdescribed, the catheter may be inserted through the interatrial septumwith its distal end suspended in the left atrium. In the case of aflexible catheter, movements at the septum may not be translatedlinearly to the catheter tip. Therefore, there may be relative movementbetween the distal end and the portion passing through the septum. Thismay be reduced by coupling the distal end to the portion passing throughthe septum. In a preferred embodiment, the catheter shaft between andincluding the distal end and the portion passing through the septum maybe made rigid. Referring to FIG. 24, the catheter shaft 670 may becomprised of stacked elements 671. The elements 671 may be domed disksor collar segments with domed ends which are mechanically coupled by astructure 672. The structure 672 may connect the centers of the elements671, as shown, in a flexible manner so that the shaft 670 may be shapedin any desired geometry suitable for use in the tissue modificationtreatment. Once a desired shape is formed, the structure 672 may berigidified to hold the shape. Such rigidity may allow any movement ofthe interatrial septum to be translated to the distal end of thecatheter shaft, thus coupling the catheter to the movements of theheart. This may improve stabilization of the devices and systems used inthe tissue modification treatment. It may be appreciated that a variablyrigid shaft as described may be utilized for coupling to any cardiacfeature and may be used with or as part of any device component ordevice in the procedure. Thus, the feature may be utilized to lock anydevice component, catheter or tool into place once it has beenmanipulated into a desired shape. This may be useful in a variety ofsituations in addition to those mentioned above.

Stabilization against the valve may be most useful when approachingantegrade with atrial or atrial-ventricular devices, however it may alsobe useful when approaching retrograde with ventricular oratrial-ventricular devices. When approaching antegrade, stabilizationmay be most easily achieved by coupling one or more components of thedevice to the atrial walls, valve annulus, valve leaflets, and/or valvecommissures.

Coupling to the atrial walls may be accomplished by a number ofstabilization mechanisms. In each embodiment, structures such as wires,ribbons, mesh, cages or balloons extend outwardly from the device,contacting and applying radial force to the atrial walls. Such contactmay couple the movements of the atrium with the device forstabilization. A preferred embodiment is shown in FIG. 25. Here,flexible wires 680 bend out radially from the catheter shaft 681 withcurved portions contacting the atrial walls AW. It may be appreciatedthat any number of wire patterns or means of extending from the shaftmay be utilized, as mentioned above.

Coupling to the valve annulus may also be accomplished by a number ofstabilization mechanisms, many of which include simultaneous coupling toother valve features, such as the leaflets and/or commissures. Inpreferred embodiments, such stabilization mechanisms may be comprised ofloops, rings, wings, petals, arms, and the like. Coupling can beenhanced by varying surface friction and/or combining structures withvacuum. One or more of these mechanisms may be present, typicallyextending radially from a central shaft. When two elements are present,they are commonly placed 90 to 180 degrees, preferably 120 to 180degrees, apart around the central shaft. More than two elements aretypically arranged in a radial pattern around the central shaft.Structure, size, angle and arrangement may be adjustable to fitindividual patient anatomy.

Examples of such embodiments are shown in FIGS. 26-29. Referring to FIG.26, a guide catheter 14 may have deployable adjustment wires 20 to serveas a stabilization mechanism. The wires 20 are typically attached at oneend to the distal tip of the guide catheter 14 and may be advanced attheir other ends so that they selectively deploy from the guide catheterto engage the mitral valve MV. The adjustment wires 20 may act tostabilize or anchor the guide catheter relative to the mitral valve MVby coupling to the valve annulus, leaflets or commissures.

Similarly, the guide catheter 14 may have any number of stabilizationelements, as illustrated in FIGS. 27-29. As shown in FIG. 27, thestabilization elements may be comprised of a number of petals 22arranged around the distal tip of the catheter 14. Similarly, thestabilization element may be a single large loop 25, as depicted in FIG.28. Alternatively, the interventional catheter 30 may have a pluralityof stabilizing arms 34 (FIG. 29) which both position and anchor thedistal tip of the interventional catheter 30 relative to the valveannulus. Usually, at least three stabilizing arms will be utilized, withfour being illustrated, however any number may be used. The stabilizingarms 34 may be pre-shaped, resilient metal rods (for example, formedfrom nitinol or other shape memory or superelastic alloy), ribbons,tubes, polymers or composites thereof that may be selectively extendedfrom the tip of the interventional catheter 30 to engage the valveannulus. The interventional catheter 30 of FIG. 29 is shown with aseparately extendable interventional tool 36 which performs the desiredvalve or tissue modification, as described in more detail below. Suchstabilization elements may preferably engage the annulus located aboutthe mitral valve MV and apply forward pressure against the annulus tomaintain contact and provide axial stabilization.

Stabilization may also be achieved by applying radial pressure to thecommissures. As shown in FIG. 30, a pair of stabilization elements 32may extend radially from a guide catheter 14 or interventional tool 30to contact the commissures. The distance between the elements 32 may beequal to or slightly greater than the distance between the commissuresto apply radial force against the commissures. The stabilizationelements 32 may be comprised of any suitable material, such as nitinol,stainless steel, plastic or any combination thereof, of any consistentor variable flexibility, and any cross-sectional shape, such as roundwire, flat ribbon or hollow tube. As shown in FIGS. 31A-31D, the shapeof the stabilization element may be of any suitable symmetrical ornonsymmetrical geometry, including but limited to triangular (FIG. 31A),rectangular (FIG. 31B), circular, oblong, double-humped (FIG. 31C) orsingle-humped (FIG. 31D). It may be appreciated that such stabilizationmechanisms may also serve in orientation assessment, particularly as theframe 626 (FIG. 20) previously described. Thus, they may be echo orfluorogenic or treated for such effects. In addition, it may beappreciated that such stabilization elements may be passive, i.e.,pre-sized and shaped to fit the patient anatomy so that they engage thevalve annulus without adjustment, or may be active so that they can beused to steer the guide catheter as previously described.

A number of stabilization mechanisms apply both radial and axialpressure to the valve for stabilization. For example, the double-humpedelement, shown in FIG. 31C, has a superior hump 700 which may protrudeinto the left atrium, contacting the superior aspect of the annulus andpossibly the left atrial wall, and an inferior hump 701 which mayprotrude into the left ventricle, contacting the inferior aspect of theannulus and possibly the left ventricle wall or chordal tissue. Thesuperior hump 700 may apply a downward axial force on the annulus andthe inferior hump 701 may apply an upward axial force. The waist 702between the humps may be dimensioned or adjustably sized to fit betweenthe commissures and to apply a radial force on the commissures.Similarly, a single-humped element, shown in FIG. 31D, may providesimilar stabilization without the added support from the protrudinginferior hump. Additionally, this design may be easier to position inthe mitral valve.

The last general category of stabilization mechanisms for descriptivepurposes is stabilization against the chordae. Stabilization against thechordae may be most useful when approaching retrograde with ventricularor atrial-ventricular devices. Coupling to the chordae may be useful instabilization for tissue modification to the valve, the chordae, theannulus or a combination of these. When modifying the valve, the contactwith the valve structures (typically grasping of the valve leaflets) maystill be necessary. However, when modifying the chordae, additionalcontact (such as grasping the chordae) may not be necessary since thestabilization methods may include this step. Therefore, stabilizationagainst the chordae will be discussed in Section VIII Grasping.

VII. Immobilization

Immobilization refers to substantially retarding or diminishing themotion of the cardiac structures or intermittently or temporarilystopping the cardiac cycle. This may be accomplished with a variety ofmethodologies. First, drugs may be injected to temporarily slow or stopthe cardiac cycle. Such drugs may include but are not limited toesmolol, adenosine, isofluorane and transarrest mixture, with or withoutelectrical pacing. Likewise, induced atrial fibrillation may interruptthe cardiac cycle.

Mechanical immobilization of the valve can be effected in a variety ofways. Most simply, valve action can be diminished or stopped by raisingthe pressure in the associated ventricle to a pressure above that in theatrium during diastole. For example, a suitable liquid can be infusedinto the ventricle to raise the intraventricular pressure, or the aorticvalve could be temporarily incapacitated allowing aortic regurgitationand raising the ventricular diastolic pressure. Alternatively,interventional tools and/or catheters carrying such tools may simply bemechanically stabilized against the valve, valve annulus, valvecommissures, ventricular wall, atrial wall, generally as describedabove.

Mechanical valve immobilization will usually involve more interactionwith the valve than simple stabilization. Immobilization will usuallyinvolve either capture and immobilization of either or both valveleaflets (or all three valve leaflets in the case of a tricuspid valve)or capture and immobilization of the chordae. For example, balloons ormesh cages may be used and placed under one or both leaflets to holdthem partially closed. By temporarily immobilizing or adjusting thevalve action, such as changing the point of coaptation, it is possibleto see if a particular modification will be sufficient to treat theregurgitation. For example, by temporarily grasping the valve leafletsat a particular point and holding the leaflets together, it can bedetermined whether a permanent suturing, stapling, or other affixationat that point will achieve a sufficient reduction in regurgitation. Whenthe heart is beating, valve regurgitation can be examined in real timevia conventional imaging techniques, such as TEE. If the temporary valvemodification appears sufficient, it can then be made permanent using anyone of a variety of interventional techniques.

VII. Grasping

Valve or tissue modifications or interventions most commonly requiregrasping a portion of the valve or tissue to be modified. Such graspingmay be useful in adjusting tissues (such as coapting valve leaflets) forappropriate modification, checking the positioning of the tissues forimproved biological function, and stabilizing or immobilizing the tissuefor the modification procedure. As previously described, such graspingmay also be useful to stabilize another tissue which will be modified inthe procedure, such as the grasping the chordae to stabilize the valvefor valve modification. Since the most common procedures may involvevalve modification or chordal modification, grasping of these cardiacstructures will be discussed. However, it may be appreciated thatdescribed grasping devices, systems and methods may apply to any cardiacor other structure.

A. Chordal Grasping

Grasping of the chordae may involve capturing and anchoring the chordae,as illustrated in FIGS. 32-40. As shown in particular in FIGS. 32A and32B, a guide catheter 40 can deploy a first capture coil 60 and a secondcapture coil 62 through a pair of deployment catheters 64 and 66,respectively. The coils will be positioned while visualizing so that thefirst coil 60 captures chordae attached to a first valve leaflet LF andcoil 62 captures chordae attached to a second valve leaflet LF. Thecapture coils will typically be elastic wires, preferably composed of asuperelastic material such as nitinol, which are delivered through thedeployment catheters in a straightened configuration. When they areadvanced out of the deployment catheters, the capture coils will assumea helical or other configuration that can be advanced into and entanglethe chordae.

The coils 60 and 62 may then be brought together laterally preferablycoapt the leaflets LF together by advancing a retaining ring 68 which issecured at the distal end of a deployment wire 70, as illustrated inFIG. 32B. The leaflets are thus brought together and immobilized for asubsequent intervention. Alternatively, if immobilization via the coils60 and 62 is sufficient in itself, it will be possible to make thedeployment permanent. It is a particular advantage of the temporaryimmobilization that the valve action can be examined via the real timeimaging techniques to see if regurgitation has been adequatelyaddressed. If it hasn't, the coils can be redeployed or the relativepositions of the two coils 60 and 62 can be changed until an adequatepair has been effected.

It will be appreciated that if a subsequent interventional step isrequired, it can be made from either an antegrade or retrogradeapproach. A variety of specific interventional techniques are describedin detail hereinbelow.

An antegrade approach for deploying a single chordae snare 74 andoptionally securing a suture loop about the captured chordae isillustrated in FIGS. 33A and 33B. A guide catheter 14 deployed over theleaflets LF of the mitral valve MV may be deployed as describedpreviously. A pair of deployment catheters 76 and 78 are advanced fromthe distal end of the guide catheter 14 and observed in real time viaany of the imaging techniques described previously. The pre-shaped snare74 is advanced out of the first deployment catheter 76 and is advancedthrough both of the chordae CT, as illustrated in FIG. 33A. A captureloop 80 is advanced from the second deployment catheter 78 andpositioned so that it lies in the path of the pre-shaped snare 74 as itis advanced through the chordae CT. After a capture tip 82 passesthrough the capture loop 80, the loop can be tightened to secure to thecapture tip 82 and draw the tip into the second deployment catheter 78.The capture tip 82 is attached to an end of a length of suture 84 (FIG.33B) which runs back through a lumen in the snare 74. In this way, thesuture may be pulled into the second deployment catheter 78, while thesnare 74 is withdrawn back into the first deployment catheter 76,leaving only the suture in place grasping both the chordae. By thentying or otherwise securing the suture together into a permanent loopthrough the chordae, the coaptation of the valve leaflets LF can bemodified in a desired way. As with the previous embodiments, aparticular advantage of this approach is that the valve coaptation canfirst be viewed using the real time imaging capability to assure thatvalve regurgitation is adequately addressed before making the chordaecapture permanent.

An alternative technique for deploying suture to capture chordae CT isillustrated in FIG. 34. First deployment catheter 90 (positioned througha guide catheter which is not shown) is positioned through the openingbetween valve leaflets LF. A balloon 93 at the distal end of chordaesnare 92 is extended through the chordae, as described previously. Theballoon 93 is inflated and floated through the mitral valve duringregurgitation. The balloon will pass through the previously deployedcapture snare 95. Alternatively, the chordae snare 92 could be shaped sothat it will encircle the chordae and then pass outwardly through thevalve opening and into the previously deployed capture snare 95.

A chordae stabilization catheter 100 which is particularly suited for aretrograde approach is illustrated in FIG. 35. The catheter 100 includesa catheter body 102 having a pair of lumens 104 and 106 extending from aproximal end (not shown) to a distal end which is illustrated in FIG.35A. The main lumen 104 extends fully to the distal tip of the catheterbody 102 and a chordal snare 108 is slidably received in the lumen. Thesnare 108 has a loop pre-formed over its distal end so that, whenextended from the catheter 100, it will assume the shape shown in FIG.35. The loop has a diameter generally in the range from 3 mm to 20 mmand is shaped so that it will evert backwardly into a secondary loopformed by a capture snare 112. The capture snare 112 is disposed in thesecondary lumen 106 and emerges from an opening 114 space proximallyfrom the distal end of the catheter 100. The distal tip of the capturesnare 112 is fixed at an anchor point 116 in the distal tip of thecatheter body 102. Thus, by extending and retracting the capture snare112, the capture loop can be moved between the position shown in fullline and broken line.

Referring now to FIGS. 36A and 36B, use of the catheter 100 forcapturing and stabilizing chordae CT will be described. The catheter 100is introduced in a retrograde direction (although antegrade would alsobe possible), typically through a guide catheter 40 as generallydescribed above. Under direct (e.g., fluoroscopic) observation, thedistal end of the catheter 100 will be guided to a position generallywithin the chordae CT, as illustrated in FIG. 36A. The chordae snare 108will then be extended from the distal tip so that it passes through andbecomes entangled with the chordae CT attached to both of the leafletsLF. The distal tip of the chordal snare 108 will eventually pass throughthe loop defined by the capture snare 112, also as illustrated in FIG.36A. The capture snare will then be tightened to hold the distal tip ofthe chordae snare 108, and the chordae snare then retracted so that theloop of the snare which passes through the chordae will be tightened,generally as shown in FIG. 36B. Generally, the catheter 100 will not beintended for permanently affixing the chordae CT. Instead,immobilization of the valve leaflets LF will be intended to facilitate asubsequent treatment step, as described hereinafter. Use of theretrograde approach for immobilizing the chordae CT will be particularlyadvantageous when used with antegrade interventions.

The catheter of FIG. 35 could, however, be modified to facilitateperformance of retrograde interventions while the chordae arestabilized. As shown in FIG. 37, the catheter 120 includes a catheterbody 122 which is generally the same as that shown for catheter 100 inFIG. 35 (with common components being given identical referencenumbers), except that a third working lumen 124 is provided. The workinglumen 124 can be used to deliver and position a wide variety ofinterventional tools for performing at least most of the specificinterventions described elsewhere in this application. The catheter 120will, of course, be particularly useful for performing interventionswhich rely on retrograde stabilization of the chordae CT of the typeprovided by the catheter. For example, the lumen 124 may be used toposition an RF energy delivery tool for heating the chordae to causeshrinkage, as described in more detail below. Alternatively, the workinglumen 124 could be used to position a chordae stabilization coil 130,generally as described in FIGS. 39A and 39B. The coil is typically ahelical filament having a secondary helical structure comprising, forexample, three major loops. The coil may comprise an inner elementcomposed of a shape memory material, such as nitinol, inserted into anouter coil 132 made of a radiopaque material, such as a platinum alloy.The shape memory coil 134 is formed into a “stacked coil” configuration(with no space between adjacent windings of the coil) and thenprogrammed so that it will assume the stacked coil configuration at atemperature slightly above body temperature. The coil assembly 130 isformed by heat treating the platinum 132 to a diameter D1 and length L1,as shown in FIG. 39A. The shape memory coil 134 is then stretched to anear linear configuration and inserted into the platinum coil 132, andthe two are coupled at the end. Upon heating, the shape memory coilcontracts back into its tightly stacked coil shape, compressing theplatinum coil 132, and causing the entire assembly 130 to assume asmaller diameter D2 and length L2, as shown in FIG. 39B. The coil 130may be delivered using a pusher catheter through the working lumen 124so that it deploys within and entangles the chordae CT, as shown in FIG.40. The pusher catheter (not shown) could be configured similarly toembolic coil delivery catheters, such as those described in U.S. Pat.Nos. 5,226,911; 5,234,437; 5,250,071; 5,261,916; 5,312,415; 5,350,397;and 5,690,671, the full disclosures of which are incorporated herein byreference.

B. Valve Leaflet Grasping

Valve leaflet grasping may be accomplished using a number of methods,most commonly the following three: 1) pinching, 2) partially or fullypenetrating or piercing, and 3) the use of suction or vacuum. Pinchinginvolves grasping the surface or edge of the leaflet without penetratingthe tissue. This may be accomplished by an antegrade or retrogradeapproach using atrial, ventricular or atrial-ventricular devices. It maybe appreciated that although the following embodiments are exampleswhich are described relative to a specific approach (antegrade orretrograde), each device or component may be used or adapted to be usedin all approaches.

In preferred embodiments, depicted in FIGS. 41-43, pinching of the valveleaflets LF can be achieved, for example, by using a grasping catheterintroduced in a retrograde direction to temporarily capture the freeends of the valve leaflets LF. It may be possible to use a simpletwo-jaw tool at the distal end of a catheter to capture both opposedleaflets. Such a two-jaw tool 710 is depicted in its open position inFIG. 41A. In this position, opposing jaws 711 may be positioned onopposite sides of the free ends of the valve leaflets LF. In its closedposition, depicted in FIG. 41B, the leaflets may be drawn together andpinched to immobilize the valve. Although this may be adequate, it maybe preferred to use a three-jaw capture tool as shown in FIGS. 42-43.The catheter 140 can be delivered through a guide catheter generally asdescribed above. The catheter includes a tool 142 at its distal end.Tool 142, as best shown in FIG. 42B, includes a fixed center jaw 144 anda pair of pivotable outer jaws 146 and 148. The jaws 146 and 148 may beindependently opened to a “capture” position as shown in broken line inFIG. 42B. Actuation of the jaws 146 and 148 may be achieved in a varietyof conventional manners, including pull wires, push wires, inflatableballoons, heat memory alloy motors, and the like. By independentlyopening and closing the capture jaws 146 and 148 against the fixed jaw144, the valve leaflets LF can be captured independently.

As shown in FIG. 42A, a first leaflet LF can first be captured. Thecatheter 140 can then be manipulated and positioned, typically underreal time imaging, to capture the second leaflet LF, as shown in FIG.43. It will be appreciated that independent capture of the leafletsgreatly facilitates the procedure. Use of a single pair of capture jawsrequires that the leaflets be captured at the instant when they areproperly opposed. In the case of prolapsed valves, such an instance maynever occur. Once captured and immobilized, as shown in FIG. 43, thevalve leaflets can then be modified in any one of a variety of ways, asdescribed elsewhere in the application.

Additional embodiments, depicted in FIGS. 44-46, involve pinching of thevalve leaflets LF by using a grasping catheter introduced in anantegrade direction to temporarily capture the surfaces or the free endsof the valve leaflets LF. Referring to FIGS. 44A-44D, the valve leafletsLF may be pinched between a superior loop 720 and an inferior loop 721.In a preferred embodiment, the grasper is comprised of a nitinol flatribbon heat set in the shape of double loops 720, 721. The ribbon may bemounted on a series of three coaxial shafts, an interior shaft 725, acentral shaft 726 and an exterior shaft 727. The distal end of theribbon may be attached to the distal end 730 of the interior shaft 725,a midportion of the ribbon may be attached to the distal end 731 of thecentral shaft 726, and the proximal end of the ribbon may be attached tothe distal end 732 of the exterior shaft 727. One or more ribbons may bemounted on the coaxial shafts; in this example, two ribbons are shown180 degrees apart. When extended, as shown in FIG. 44A, the grasper maybe pulled flat against the shafts 725, 726, 727 for ease of insertionthrough a guide catheter or tool and into a desired position between thevalve leaflets LF. When the central shaft 726 is retracted or theexterior shaft 727 advanced, as shown in FIG. 44B, the superior loops720 may extend radially from the shafts. The superior loops 720 may reston the superior surface of the valve leaflets LF in the atrium, as shownin FIG. 44D. In this position, the superior loops 720 may aid inorientation assessment, as the superior loops may be echo or fluorogenicand may be easily visible in relation to the cardiac structures or otherdevices or components. When positioned in a desired location, theinterior shaft 725 may then be retracted, as shown in FIG. 44C, toextend the inferior loops 721 radially from the shafts. The inferiorloops 721 may be in contact with the inferior surface of the valveleaflets LF in the ventricle. Thus, the valve leaflets LF may be pinchedbetween the inferior loop 721 and superior loop 720. It may also beappreciated that the inferior loops 721 may be deployed prior to thesuperior loops 720.

Referring to FIGS. 45A-45B, the valve leaflets LF may be pinched betweena superior roller 750 and an inferior roller 751. As shown in FIG. 45A,the rollers 750, 751 may be mounted on a shaft 755 and connected by apull actuation wire 756. The rollers 750, 751 may be serrated or surfacetreated in a directional pattern to facilitate grasping of the valveleaflets LF. To grasp a leaflet LF, the rollers 750, 751 may be placedagainst the surface or free edge of the leaflet LF. Pulling of theactuation wire 756 may rotate the superior roller 750 and inferiorroller 751 toward each other. This may draw the leaflet LF between therollers 750, 751, as shown in FIG. 45B. Thus, the leaflets LF may beindividually grasped for treatment.

Referring to FIGS. 46A-46B, the valve leaflets LF may be pinched betweena pair of flat coils 770. In a preferred embodiment, each coil 770 maybe comprised of nitinol flat ribbon heat set in the shape of a coil. Asshown in FIG. 46A, the coils 770 may be linked together with opposingcurvature by a clip 772. Movement of the clip 772 along the coils 770may uncurl the coils 770 to a straightened configuration. As shown inFIG. 46B, this may also be accomplished by a catheter shaft 773 placedover the coils 770. In the straightened position, the coils 770 may beinserted between the valve leaflets LF in an atrial-ventricular positionso that the distal ends 775 of the coils 770 are in the ventricle. Asthe shaft 773 or clip 772 is retracted, the coils 770 may begin curlingradially beneath the valve leaflets LF and upwardly so that the distalends 775 of the coils 770 contact the inferior surface of the valveleaflets LF. Similarly, if the coils 770 continue curling, a portion ofthe flat ribbon proximal to the distal end 775 may contact the valveleaflet. In this manner, the leaflets may be grasped for treatment. Sucha grasping device may also serve as a fixation device with the pair ofcoils 770 left in place, as will be described in a later portion of theapplication.

A valve or tissue structure may also be grasped by atraumatic partial orfull penetration or piercing. This may be accomplished with a variety ofgrasping mechanisms. Preferred embodiments include one or more prongsextending from an interventional tool in an arrangement to grasp aspecific structure. Specifically, three opposing prongs may extend froma grasping sheath with distal ends configured to pinch, partiallypenetrate or pierce. Such ends may be pointed or may be soft, as in thecase of rounded, urethane coated or solder coated ends. Referring toFIG. 47A, the opposing prongs 800 may be retracted into a graspingsheath 801 to hold the prongs 800 in a closed configuration. It may bepreferred to orient the device to a desired position in thisconfiguration. When the target tissue has been located, the prongs 800may be extended to grasp the tissue structure, as shown in FIG. 47B.This may be accomplished by either extending the prongs 800 axially orretracting the grasping sheath 801. The target tissue may be pinched,partially penetrated or pierced with the prongs 800 in thisconfiguration, or such action may be facilitated by closing or partiallyclosing the prongs 800 as previously depicted in FIG. 47A.Alternatively, the prongs 800 may be attached to or integral with aprong-tipped tube 802, as shown in FIG. 47C. Such a design may be moreconducive to the insertion of tools or fixation devices for furthertreatment steps, such as tissue modification. Tools or devices may beinserted through a lumen in the prongtipped tube 802, depicted by arrows804, for use at or near the grasping location. Similarly, tools orfixation devices may be inserted through a lumen in a hollow prong 806,as depicted in FIG. 47D. Here, one or more prongs 806 may be hollow, andthe remaining prongs 808 may be comprised of solid wire or a suitablematerial. Tools or devices may be inserted through a lumen in the hollowprong 806, depicted by arrows 810, for use at or near the graspinglocation. Prongs, hollow or solid, may be made from stainless steel,NiTi, plastic or other suitable material. Additionally, they may becoated or coiled to enhance visibility. Likewise, the geometries of theprongs may be varied to facilitate grasping of the desired amount oftissue. And, the distal tip sharpness and surface finish can be variedto establish the amount, if any, of piercing.

In addition to directly engaging the valve leaflets to effectstabilization and/or immobilization with the grasper devices describedabove, the present invention may also employ a catheter or other toolhaving vacuum or suction applicators to temporarily capture the valveleaflets. As shown in FIG. 48, a catheter 812 comprises a shaft having apair of vacuum applicator rods 813 and 814. Usually, the vacuumapplicator rods 813 and 814 will comprise separate shafts which may beaxially translated relative to the main shaft of the catheter. Furtheroptionally, the shafts could be articulated or otherwise manipulable sothat they can be independently positioned relative to the valve leafletsor other tissue structures once the catheter 812 is in place. The vacuumapplicators have one or more apertures to permit contact and adherenceto tissue when the applicators are attached to external vacuum sources.Usually, the shaft will be placed across the valve, either in anantegrade or retrograde fashion, and the applicators positioned to graspand manipulate the valve leaflets. Optionally, the catheter 812 maycomprise additional stabilizing and/or steering wires of the typepreviously described. For example, a steering wire 815 (and optionally asecond steering wire on the opposite side) may be provided for engagingagainst the valve commissures to permit positioning of the catheter withrespect to the valve leaflets. The vacuum applicators would further beindependently positionable to engage the valves in the desired fashion.Using this catheter, the leaflets can be grasped and the competency ofthe valve evaluated using the methods described previously. The valveadjustment can then be effected using any of the interventionalapproaches described herein. Further, it may be appreciated that in eachembodiment, timing of grasping may be facilitated by the use of gatingwith the patient's EKG, pressure waves of the cardiac cycle, audio heartsounds, electronic pressure or contact sensors on the graspers.

VIII. Coaptation, Adjustment and Evaluation

Once the valve leaflets, chordae or tissue structure is grasped by aninterventional tool, the tissue may be manipulated to achieve a desiredresult, such as improvement in valve function. Such manipulation mayoccur during the grasping step, or it may require a separate stepfollowing grasping. In the case of leaflet modification, valve leafletsmay be coapted or brought together and held in a preferred apposition.The valve function may then be evaluated for indications of improvedvalve function, such as reduced regurgitation. If further improvement isdesired, the valve leaflets may be additionally manipulated or adjusted.Adjustment should primarily occur in a superior/inferior (up/down)motion in order to bring the leaflets to a final positioning whereregurgitation is minimized. During adjustment, one or both leaflets maybe released and recaptured with new positioning. After the finalevaluation, the valve leaflets may be fixated in the desired position byan appropriate fixation device. In the case of chordae shortening orother tissue modification, similar steps may be taken.

IX. Tissue Modifications

Repair of atrioventricular or other cardiac valves according to thepresent invention is effected by modifying the valve or a supportingtissue structure in some way to affect blood flow through the valveduring a phase of the cardiac cycle, for example to permit blood flowthrough the valve during diastole when the associated ventricle isfilling with blood but which inhibits or prevents blood regurgitationback through the valve during systole. A number of techniques formodifying the valve closure by capturing or grasping the chordaeattached to each valve leaflet have been described above. Thesetechniques are often used just for valve grasping and/or coaptation andadjustment prior to a separate valve modification step, but they mayalso be made permanent to provide the final valve modification. Othertechniques for more directly modifying the leaflets or other supportingstructures of the atrioventricular valves will be described in thissection. These techniques may be utilized either with or without thevalve grasping and/or coaptation and adjustment techniques describedabove. For purposes of simplicity, however, the following methods willgenerally be described without specifically illustrating such grasping,coapting and adjustment approaches, focusing primarily on the methodsand devices involved with fixation. In addition, it may be appreciatedthat although the following embodiments are examples which are describedrelative to a specific approach (antegrade or retrograde), each deviceor component may be used or adapted to be used in all approaches.Further, although devices and methods are described for fixatingspecific tissues, such as valve leaflets or chordae, such devices andmethods may be used for any cardiovascular tissues and the like.

A. Fixation of Valve Leaflets

Suture can be delivered through the valve leaflets and then tied in amanner analogous to an open surgical procedure. In one embodiment, asuturing tool 200, shown in FIG. 49, may be positioned at the distal endof an interventional catheter. The interventional catheter will usuallybe advanced in an antegrade direction (i.e., from above the mitralvalve), either directly through a guiding catheter or through a workinglumen in a stabilization catheter. The tool 200 carries a length ofsuture 202 attached to a pair of needles 204 at either end thereof. Thesuture may be comprised of conventional suture material or of wire,typically stainless steel, nitinol or other material. The needles areheld on a reciprocating shaft 206 disposed within a lumen of a retrievalsheath 208. The tool 200 can be positioned to capture the opposed freeends of the mitral valve leaflets LF, generally as shown in FIG. 49. Theneedles can then be advanced through the leaflets LF by drawing theshaft 206 toward the sheath 208 so that the needles 204 penetrate theleaflet and are captured in needle receptacles 210 formed in the sheath208. The sheath can then be withdrawn. A knot can be tied in the suture,and the knot then advanced through the associated catheter to tightenover the valve leaflets. The tool 200 can carry two, three, four, oreven more lengths of suture which may be simultaneously or sequentiallyintroduced into the valve leaflets in order to permit multiple sutureloops to be placed. The resulting tied suture loops will be similar tothe “bow tie” sutures placed in open surgical procedures which have beendescribed in the medical literature as described above.

The need to place and draw long lengths of suture through the valveleaflets can, however, be deleterious to the fragile leaflet structures.Thus, alternative needle and suture devices which rely on mechanicalfasteners in relatively short suture lengths may be preferred. In oneembodiment, a hollow suturing coil 1300, shown in FIG. 49A, may bepositioned at or near the distal end of an interventional catheter. Thesuturing coil 1300 may be comprised of any material of sufficientrigidity to pierce and penetrate through valve leaflets LF, such asstainless steel, various shape memory or superelastic materials, metalalloys and various polymers, to name a few. The hollow suturing coil1300 may contain a suture 1302 comprised of conventional suture materialor of wire, typically stainless steel, nitinol or other material. Thesuture 1302 may be secured at the tip 1304 of the coil 1300 with atoggle rod 1305. After the valve leaflets LF have been grasped andcoapted, the suturing coil 1300 may be advanced in a corkscrew fashionthrough the valve leaflets LF, as shown in FIG. 49A. Though suchadvancement is shown from above, advancement may be made from anydirection through any number and configuration of valve leaflet layers.When advancing, the sharpened tip 1304 of the coil 1300 may piercethrough the leaflets LF any number of times. It may be appreciated thatsuch corkscrew piercing may be made through the middle portions of theleaflets such that a pierce is made at each half-rotation, or thepiercings may be made along the edges of the leaflets such that a pierceis made at each full-rotation, to name a few.

Once the coil 1300 has advanced to a desired location, the toggle rod1305 may be secured against a leaflet LF to hold the suture 1302 inplace. At this point, the coil 1300 may be removed by retracting thecoil 1300 in a reverse corkscrew fashion, as depicted in FIG. 49B,leaving the suture 1302 behind. Since the coil 1300 may be much largerin diameter than the thickness of the leaflets (to aid in placement),the suture 1302 may be loose-fitting and the valve leaflets LFinsufficiently modified. The suture 1302 may then be tightened, as shownin FIG. 49C, so that the suture 1302 holds the leaflets LF together in adesired configuration. This may be aided by the use of a soft-tippedcatheter 1306 which may be advanced to contact the surfaces of theleaflets LF when tightening to prevent the leaflets LF from prolapsing.Once the suture 1302 is sufficiently tight, a restrictive collar 1308may be deployed from the catheter 1306 or another device to secure andterminate the suture 1302. Such a restrictive collar 1308 may becomprised of any suitable material, such as heat-shrink tubing, nitinolshape-memory or superelastic coil or the like. Thus, this embodimenteliminates the need for needle passers and needle receivers providing asimplified method of valve leaflet fixation.

Alternatively, referring to FIGS. 50 and 51, a short length of suture220 may be positioned using a curved needle 222 which can be extendedfrom the distal tip 224 of an interventional catheter 225. The needle222 is formed from an elastic material, such as a shape memory alloy,and may be constrained in a generally straightened configuration withinthe catheter 224. When extended, as shown in FIG. 50, it assumes acurved shape so that it may be advanced through the atrioventricular orother cardiac valve leaflets LF, as shown in FIG. 51. A distal anchor226 is secured to the distal end of the suture 220 while a slideable,locking anchor 228 is placed over a portion of the suture locatedproximally to the distal anchor 226 as shown in FIG. 50. The catheter225 may be advanced to the valve leaflets LF in a retrograde approach,as shown in FIG. 51, using a guide catheter 40, as generally describedabove. The distal end 224 of the catheter 225 is positioned adjacent tothe underside of a valve leaflet, and the needle 222 then advancedoutwardly from the distal tip so that it passes through both valveleaflets.

In order to assure that the valve leaflets are in a proper orientationprior to needle advancement, the valve leaflets may be coapted andobserved using any of the techniques described previously. After theneedle has been advanced through the leaflets LF, a deployment sleeve230 is advanced to release the slideable anchoring catheter 228 from theneedle and advance it toward an underside of the valve leaflet LF. Asthe anchor 228 approaches the valve leaflet, tension on the suture 220will pull the distal anchor 226 from the needle. The deployment sleeve230 can be advanced sufficiently to draw the two anchors 226 and 228together on opposite sides of the valve leaflets, as seen in FIG. 52.The suture can then be tied off or, alternatively, locked in place usinga mechanical lock 232. If the suture is comprised of a malleable wire,as previously described, the wire may be twisted together. In eithercase, the suture is then severed and the catheter 225 withdrawn.

The anchors 226 and 228 shown in FIG. 50 are generally oval shaped andhave a length dimension which is greater than the width of the needleused to introduce them. Thus, when pulled laterally, they can sealagainst the opposed surfaces of the two valve leaflets. In someinstances, however, it will be desirable to have anchors which arecapable of expanding to a much larger dimension to assure that they donot pull through the relatively fragile tissue of the leaflets. Anexemplary expansible anchor 240 is shown in its collapsed configurationwithin a needle 242 in FIG. 53 and its expanded configuration in FIG.54. The anchor 240 is connected to a length of suture 244 and could beused with a similar slideable, expansible anchor (not shown) analogousto the non-expansible anchor 228 of FIG. 50.

Additional expansible anchors may be seen in FIGS. 55A and 55B. In thisembodiment, the anchor is comprised of an expanding randomly orientedwire coil. The coil is made from a shape memory nitinol wire that isannealed (heat set) in a straight configuration and then coiled. Asshown in FIG. 55A, different sections 820, 821 of the coil may beprocessed to have different properties by varying the diameter andtension in the coil along its length. When the coil is heated to aspecified level (T1), such as with RF energy, a designated portion 821of the coil will become a randomly oriented mass of wire 824 withself-locking struts to prevent disentanglement. When the coil is heatedto a different specified level (T2), a different designated portion ofthe coil 825 will become randomly oriented. As each portion of the coil824, 825 expands and changes shape, a full entanglement of the coils isallowed to occur, effectively compressing and fixing the two halves 824,825 of each coil together. The coil may be introduced through the valveleaflets LF with the use of a shape memory, super elastic orheat/current activated needle introducer 826. Once the valve leaflets LFare pierced, an anchor 824 may be activated and deployed distally. Theintroducer 826 may then be retracted to the proximal side of the secondleaflet LF2 and the second anchor (not shown) may be deployed in thesame manner. The amount of tension between the anchors 824, 825 may beaffected with the shape memory or super elastic properties of theexpanding anchor. It may be appreciated that the heat activatedexpanding coil may alternatively take other forms, such as a wire mesh,for example. Additional expansible anchors may be in the form ofinflatable chambers filled with a liquid that may optionally partiallyor fully solidify.

Yet another form of detachable anchor attached to a length of suture isillustrated in FIGS. 56 and 57. FIG. 56 is a front view, while FIG. 57is a side view of the same structure. A self-penetrating anchor 260attached to a length of suture 262 is carried on a pair of rods 264. Therods are mounted within an open lumen of a deployment catheter 266. Theanchor 260 can pivot on a detent structure 268 formed between the distalends of the deployment rods 264. The anchor has a sharpened distal tip270 which permits the anchor to be directly penetrated through the valveleaflet tissue when the rods are extended from the catheter 266.

Referring now to FIG. 57, the catheter 266 may be deployed over theleaflets LF of the mitral valve MV in an antegrade direction through aguide catheter 14 as generally described above. The catheter 266 can beused to deliver a pair of the anchors 260 sequentially. As shown in FIG.58, a first anchor 260 a has been deployed through a first leaflet and asecond anchor 260 b has just been placed through the second leaflet. Theanchors 260 a and 260 b are deployed by pushing them through the leaflettissue while the sharpened tip 270 remains generally in a distal orforward direction. After passing through the tissue, the anchor 260a/260 b can be turned, either by pulling back on the deployment rods 264or by pulling backwardly on the suture 262. The two ends of suture 262can then either be tied or fastened using a mechanical fastener in orderto draw the opposed leaflets into proper apposition.

Referring now to FIGS. 59 and 60, a deployment catheter 290 having aneedle 280 with sharpened distal tip 282 can be used to place sutureloops in individual valve leaflets. A needle 280 is carried on a pair ofactuator rods 284 with a length of suture 286 attached to the needle.The needle 280 is first passed through the leaflet in a generally axialorientation with respect to the catheter 290. After passing through theleaflet from a guide catheter 14, as shown in FIG. 60, the needle iscanted at an angle from 20° to 30° and passed back through the leafletat a different position. A locking groove 288 on the needle is capturedon a bar 292 in the distal end of the catheter 290. The needle 280 maythus be detached from the rods 284 to pull suture 286 in a loop backthrough the leaflet. This way, loops of suture may be placedsuccessively through both leaflets LF of a mitral valve MV, as shown inFIG. 60. The suture loops may then be tied off, connected withfasteners, fused together using RF, microwave or ultrasound energy, orotherwise secured to close the valves together in a desired apposition.

In addition to sutures and suture-based devices, as just described,opposed points on the valve leaflets and/or chordae can be attached witha variety of staples and tissue-penetrating fasteners. The staples andother fasteners can be delivered through guide catheters, generally asdescribed above, and may be positioned during or after valve grasping,coaptation and adjustment, also as described above.

Referring now to FIGS. 61A and 61B, staple applying catheter 300 isschematically illustrated. Typically, the leaflets LF of a mitral orother atrioventricular valve will first be accessed by any of thetechniques described above. The catheter 300 will then be introduced ina retrograde fashion, for example, as illustrated previously. A staple302 is held in an open position at the distal tip of the catheter 300and has a generally W-shaped profile with two recesses for receivingeach of the leaflets LF, as shown in FIG. 61A. After proper positioningis confirmed visually, the staple 302 may be closed over the leaflets sothat the tips penetrate opposed points on each leaflet by pulling on anactuator cord 304, as shown in FIG. 61B. The actuator cord can then bedetached and the catheter 300 withdrawn, leaving the staple 302 in placeto hold the leaflets together. Optionally, additional clips can beplaced in a like manner to further strengthen the affixation of theleaflets. As described, the clip is a malleable clip which undergoesplastic deformation for emplacement. Alternatively, the clip could beformed of an elastic material, such as a shape memory alloy, and held inits open position as shown in FIG. 61A. The clip could then be placed byreleasing it to return to its memory (closed) configuration, as shown inFIG. 611B. Other actuation mechanisms could also be used, such as theuse of heat to induce a shape change in a heat memory alloy staple.

In addition, two part snaps, rivets and staples may be used to holdleaflets in place by locking together. This may be achieved by a numberof device designs. Preferred embodiments involve two disks 850,pledgets, or the like, placed on opposite sides of tissues or leafletsLF to be bound together, as shown in FIG. 62A. Typically a shaft 852,pin or needle may pierce the leaflets LF and connect the two disks 850.The disks 850 may then be snapped or joined together by interlocking oneor both disks 850 to the shaft 852 and/or portions of the shaft 852 toeach other. Such a fixation device may be introduced through a lumen ofa specialized catheter 854, introducer or component of an interventionaltool, as shown in FIG. 62B. The disks 850 may be solid and/or rigidrequiring placement on each side of the tissue, or the disks 850 may beflexible, collapsible and/or inflatable such that they may be insertedthrough the tissue for placement on the other side of the tissue.Preferred embodiments also involve two disks 855, pledgets, or the like,which are placed between tissues or leaflets LF to be bound together, asshown in FIG. 62C. Here, the disks 855 have penetrating prongs 856 ateach end to pierce and grasp tissue. When the disks 855 are snapped orjoined together by interlocking one or both disks 855 to a shaft 858,shown in FIG. 62D, and/or portions of the shaft 858 to each other, theleaflets LF may be bound together.

An additional embodiment of a two part rivet-like stapling mechanism isillustrated in FIG. 63. A stapling mechanism 322 at the distal end of acatheter 320 comprises a first jaw 324 which carries a fastener 326 anda second jaw 328 which carries a retaining ring 330. The fastener has acollapsible cone 332 at its distal end so that it may be forced into anaperture 334 in the retaining ring 330. The jaws 324 and 328 arepivotally mounted within the distal end 340 of the catheter so that theymay be opened and closed to grasp the free ends of the valve leafletstherebetween. The closing of the jaws 324 and 328, however, does notlock the fastener 326 into the retaining ring 330. Thus, the valveleaflets can be temporarily grasped and the improvement in valveregurgitation visually assessed. If the improvement is sufficient, thefastener 332 can be driven into the tissue and locked in the retainingring 330. If the improvement is not sufficient, the jaws can berepositioned on the valve leaflets one or more additional times until anadequate or optimized repositioning of the leaflets is obtained. Thefastener 332 can be driven into the retaining ring in a variety of ways.In the illustrated embodiment, a cam device 342 is slidably mountedbehind an inclined surface 344 on the rear of the fastener 326. Bydrawing the cam actuator 342 downwardly using draw cord 348, the rivetcan be driven through the valve leaflets and into the retaining ring330, as illustrated in FIG. 64.

In addition to rivets, snaps, pins and the like, coils maybe used in asimilar manner to fix valve leaflets in a desirable arrangement, asshown in FIG. 65A. Coils 900 may be comprised of a superelastic materialand pre-shaped in a coil configuration for engagement with the leaflets.The coil 900 may be advanced from an introducer sheath 902 to deploy thecoil 900 in an orientation that will approximate the leaflets incompression. Alternatively, the coil 900 may be comprised of a heat orcurrent activated shape memory material As depicted in FIG. 65B, thecoil 900 may be straightened in its initial configuration for ease ofpiercing and advancing through the leaflets LF. When positioned, thematerial may be activated by heat or current to assume a shape memorycoil configuration corresponding with FIG. 65A. Again, the coils may beoriented to approximate the leaflets in compression. To achieve maximumleaflet compression at the coaptation points, a super elastic or shapememory coil 900 may be delivered in a manner that places the coil in aninverted orientation across the leaflets, as illustrated in FIG. 65C.This may be accomplished with the use of a specialized delivery system904. When released from the delivery system 904, the distal end 905 ofthe coil produces a compressive force as the coil attempts to achieve anon-inverted orientation.

As a further alternative, a cinch-type fastener 360 may be positioned ina loop through opposed valve leaflets LF, as shown in FIG. 66. Thefastener 360 could be advanced from either a retrograde or antegradedirection, but the antegrade direction is illustrated for convenience. Apositioning catheter 362 can be introduced through a guide catheter 14which has been previously positioned by any of the techniques describedabove. After advancing the cinch-type fastener 360 through the leaflets,for example by pushing a pre-shaped fastener 360 through the leaflets sothat it returns to the distal tip of the placement catheter 360, afastening collar 364 may then be advanced to tighten the fastener loop360 until the leaflets are positioned in a desired fashion.Alternatively, the fastener 360 may be twisted to constrict the openloop. Typically, the fastener 360 has chevrons or other one-way surfacefeatures so that the locking column may be advanced and will remain inplace without loosening over time, or in the case of twisting,untwisting over time. The fastener 360 is then released and, if desired,additional fasteners positioned in a like manner. The fastening collar364 may alternatively be used to secure the sutures shown previously inFIG. 49. The collar 364 may be crimped onto the sutures 202 or locked inplace by the use of a combination of one-way surface features on thecollar 364 and sutures 202.

Further, a variety of penetrating and non-penetrating clips, barbs,grappling hooks, and the like, may be used to fasten valve leaflets in adesired configuration. As previously described as a means to grasp thefree ends of the valve leaflets in a pinching manner, a pair of flatcoils may also be used as a fixation device. As previously shown anddescribed in relation to FIG. 46A, the coils 770 may be linked togetherwith opposing curvature by a clip 772. When inserted as shown in FIG.46B, the coils 770 may be permanently joined in this orientation and mayremain as a permanent implant. Alternatively, the coils 910 may piercethe leaflets LF to hold them in place as shown in FIGS. 66A and 66B.During placement, the coil 910 may be inserted through a deliverycatheter 911 in a straight configuration and pierce the leaflets LF inthis form, allowing the free distal end 912 of the coil 910 to curlafter it has penetrated the leaflets LF, as shown in FIG. 66A. Theproximal end may then curl after it disengages from the deliverycatheter 911 to remain as an implant as shown in FIG. 66B.

Likewise, a variety of barb-like structures may be used in a similarfashion to fasten valve leaflets in a desired configuration. Referringto FIG. 67, a shaft 920 with one or several curved barb-like distal ends922 may be positioned so that the distal ends partially or fullypenetrate each leaflet LF to be fixed. The shaft 920 may be a shapememory or super elastic wire. By activating the shaft 920 with heat orcurrent, in the case of a shape memory material, or allowing the shaft920 to assume its pre-configured shape, in the case of a super elasticmaterial, several barbs 922 may be approximated to coapt the leaflets inthe desired position. On the other hand, several discontinuous barbs 922may be tensioned and coapted using a crimping or coupling and trimmingsystem. Similarly, as shown in FIG. 68, a shaft 924 with expandingbarb-like distal ends 926 may be positioned so that the distal ends 926penetrate each leaflet LF to be fixed. Here, however, the distal ends926 may be comprised of one or more struts 927 which expand to furtherprevent retraction of the shaft 924. Such expansion may be achieved byactivation of the shaft 924 with heat or current or allowing the deviceto assume its pre-configured shape. In addition to end 926 expansion,the shaft 924 may be approximated to coapt the leaflets or severaldiscontinuous shafts may be tensioned and coapted using a crimping orcoupling and trimming system.

In addition to fixation, clips may be used to draw leaflets together ina suitable coaptation configuration. While temporarily holding two ormore leaflets in a desired configuration, such as with grasping tools, aclip may be deployed to maintain the desired position or to furthermanipulate the leaflets. For example, a clip 940 may be mounted on adelivery catheter or interventional tool 942, as shown in FIG. 69A. Itmay then be positioned in a desired location to hold the leaflets LF, asshown in FIG. 69B. In the deployed and activated state, depicted in FIG.69C, the clip 940 may tend to pinch inwardly, pulling the leafletstogether, as indicated by arrows 944. This may be achieved by activationof super elastic or shape memory material. Alternatively, referring toFIGS. 70A and 70B, the clip 945 may pinch inwardly, indicated by arrows944, by manual crimping of the spine 946 or interlocking of the piercinglegs 948. When positioned appropriately between the valve leaflets LF,as shown in FIG. 70B, the leaflets may be drawn together by crimping thespine 946 of the clip 945 with the use of a removable actuator 950. Asthe actuator 950 passes over the spine 946, the spine 946 may beplastically deformed to a new configuration. Or, as the actuator 950passes over the spine 946, the proximal ends of the piercing legs 948may become interlocked. In either case, inward movement of the clip 945may be controlled by passing the actuator 950 only over portions of thespine 946 in which such pinching is desired. Therefore, a single clipmay provide variable inward forces.

Inward forces may also be applied by components of an interventionaltool, such as a by graspers. Graspers, as previously described, aredevices which grasp and hold tissues (such as coapting valve leaflets)for appropriate modification, such as fixation. Thus, graspers are mostlikely in place while a fixation device is deployed and positioned.Referring to FIG. 71, an embodiment of graspers 960 is shown holding theleaflets LF on opposite sides of a deployed clip 962. Inward force maybe applied to the clip 962 by moving or applying force to the graspers960 in an inward direction, as depicted by arrows. In a furtherembodiment, the graspers may serve as a grasping device and as animplantable fixation device. Referring to FIG. 72A, an embodiment ofgraspers 960 is shown coapting and holding the leaflets LF together. Thegraspers 960 may then be joined by a coupling device 964 and detachedfor implantation, as shown in FIG. 72B.

Because of the fragility of the tissue in the valve leaflets, it willsometimes be preferred to utilize methods or devices which do notcompletely pierce or penetrate the tissue. For example, leaflets may befused together in a desired coaptation position by applying laser, RF,microwave or ultrasonic energy at specified coaptation points. Inaddition or alternatively, external clips which are partiallypenetrating or non-penetrating may be used. A variety of deformable andelastic clips can be utilized, and clips will usually be deployed in aretrograde fashion so that an opening in the clip can be placed over theundersides of the adjacent valve leaflets.

A preferred clip-applying catheter 380 in is depicted in FIGS. 73A, 73B,and 73C. The catheter 380 has a three-jaw clip-applying device 382 atits distal end. The three-jaw structure allows the clip-applier to beused as a three-jaw grasping device before final deployment of the clip.Such grasping has been described earlier with reference to FIGS. 42A,42B, and 43 above. A center jaw 384 of the device has a tubularstructure and allows the catheter to be introduced over a guidewire 386,where the guidewire may be placed through the atrioventricular valveprior to catheter positioning. A clip 388 has a V-shaped structure andis normally closed so that a force is required to open the distal endsof the clip. Jaws 390 and 392 hold the clip and can open the clip byselectively opening either jaw, with jaw 392 shown in open in brokenline in FIG. 73A. Thus, jaw 392 may be opened first to capture a freeend of a first valve leaflet. With the catheter 380 thus attached tojust the first valve leaflet, the catheter can be repositioned so thatthe other jaw 390 can be opened and used to capture the second valveleaflet. After the valve leaflets are captured and held in a properorientation, valve improvement can be confirmed by visual observation.If improvement is sufficient, the clip can be detached from the catheterand left in place, as shown in FIG. 74.

B. Shortening of the Chordae

In addition to suturing, fastening, and otherwise physically attachingportions of the valve leaflets and/or chordae together, valve leafletclosure can be improved by shrinking portions of either or both of thechordae attached to the two valve leaflets. An exemplary catheter 400having an energy-applying coil 402 at its distal end is shown in FIG.75. Such energy may be in the form of radiofrequency (RF), microwave,ultrasound, laser, heat or current. The catheter 400 may be deployed ineither an antegrade or retrograde direction, with retrograde generallybeing preferred to facilitate access to the chordae. One or more chordaeCT are captured within the coil and RF energy, for example, applied froma conventional power supply. Application of the RF energy to thechordae, which are composed of collagen and other normal tissueconstituents, over a length L will cause shrinkage of the tissue to alength which is shorter than the original length L. Similarly, suchapplication of energy to the chordae may also be achieved with the useof an energy applying chordal snare or similar device. By applying suchshortening of the chordae, valve conditions, such as prolapsed valvescan be effectively treated.

In addition to the use of energy for shortening chordae, the chordae canbe plicated using mechanical plication devices 420, as illustrated inFIG. 76. Each of the devices 420 comprise a cap piece 422 and areceptacle 424. A receptacle has a channel 426 which receives a pin 428on the cap piece 422. There is sufficient clearance between the pin 428and channel 426 so that a portion of the chordae CT can be captured andfolded therein by placing the cap into the receptacle. Each plicationdevice 420 will thus shorten a portion of the chordae by a predeterminedamount. Multiple devices can be used to achieve a desired overallshortening of the chordae. The devices can be placed using jaw-typedevices and shortening can be visually observed by any of the techniquesdescribed above. Alternatively, chordae may be mechanically plicatedwith the use of suture loops. Referring to FIG. 77A, a suture 980 maypenetrate the chordae CT at a first location 982 and then penetrate thechordae CT again at a second location 984 forming a loop. By pullingclosed the loop, as shown in FIG. 77B, the effective length of thechordae CT is reduced. The suture loop may then be fixed and trimmed forimplantation. This may be repeated along a chordae to form multipleindividual or continuous loops, and/or it may be repeated on along morethan one chordae. Similarly, such plication may also be achieved withthe use of a shape memory or super elastic wire coil which may penetratea chordae at one or more points and draw the tissue together uponactivation.

C. Annuloplasty

The intravascular approaches of the present invention, particularly theantegrade approaches, can also be used to place supporting rings anddevices around the atrioventricular valve annulus. Such devices canprovide support which is analogous to that provided by annuloplastyrings implanted in open surgical procedures. In one approach, an elasticannuloplasty ring can be delivered through the guide catheter in acollapsed fashion, deployed to open over the annulus, and then stitchedor stapled in place using appropriate catheters.

A first exemplary annuloplasty ring 500 can be deployed using a catheter502 positioned through a guide catheter 14, as generally shown in FIG.78. The annuloplasty ring 500 is deployed as an umbrella having spokes504 which open the outer ring. After deploying the ring, it may besecured in place using sutures, staples, tissue adhesives, or otherconventional techniques. The catheter 502 may then be removed, togetherwith the deployment spokes 504, leaving the ring permanently in place.

Alternatively, an annuloplasty ring 520 can be delivered on a ballooncatheter 522 as shown in FIGS. 79 and 80. The ring 520 can be formedfrom a deformable material, and the balloon 520 inflated within thevalve annulus to expand and deploy the ring, as shown in FIG. 80. Theballoon catheter may be placed directly over a guidewire 524, but willmore usually be positioned using a combination of a guide catheter andguidewire. Once the ring 520 is deployed, it can be sutured, stapled,glued, or otherwise affixed around the valve annulus.

As an alternative to placement of discrete annuloplasty rings, the valveannulus can be reinforced and tightened by placing a plurality ofanchors, such as staples 540 about the annulus of the mitral valve, asshown in FIG. 81. A suture 542 or other filament can then be placedthrough the anchors 540 and tightened in a “purse string” fashion. Thesuture filament can then be tied off to maintain the desired tighteningand enforcement of the valve annulus.

As yet a further alternative, the valve annulus can be plicated bypositioning a plurality of staples about the annulus, as shown in FIG.82. Here, each staple 560 plicates or shortens a small peripheralsegment of the annulus. A staple applying catheter 562 may have the samegeneral structures described above in connection with FIGS. 61A and 61B.

X. Device Embodiments

The following three device embodiments depict complete device designsutilizing a variety of the specific components described above and/ornew component designs to accomplish similar objectives.

A. Atrial Device

Referring to FIG. 83, the atrial device 1000 is comprised of a cathetershaft 1002 having a distal end 1004 and a proximal end 1006. Thecatheter shaft 1002 is comprised of, among others, a conduit 1008, acoaxial outer sheath 1010, and a central guidewire lumen 1011. Towardthe distal end 1004, a pair of stabilizers 1012 having a single-humpshape (previously illustrated in FIG. 31D) are fixedly mounted on theouter sheath 1010 at their proximal end 1014 and fixedly attached orhinged to extenders 1016 at their distal end 1018. The stabilizers 1012are shown in an outwardly bowed position, however they may be inwardlycollapsed by either extending the extenders 1016 or retracting the outersheath 1010. Bowing may be achieved by the reverse process.

Referring to FIG. 84, the atrial device 1000 may be used with a typicalantegrade approach to the mitral valve MV. As previously described anddepicted in FIGS. 7 and 8, such an antegrade approach may involvepenetrating the interatrial septum IAS and maintaining such access witha guide catheter 14. The guide catheter 14 permits introduction of theatrial device 1000 to the left atrium LA and mitral valve MV. To allowpassage of the device 1000 through the guide catheter 14, thestabilizers 1012 must be in a collapsed position as shown. In addition,graspers, described below, may be fully retracted to avoid damage tocardiac structures. Thus, they are not visible in FIG. 84.

Referring to FIG. 85, the atrial device 1000 may be stabilized againstthe mitral valve MV. The stabilizers 1012 may be inserted through themitral valve MV and may be aligned with the line of coaptation C betweenthe valve leaflets LF1, LF2. To minimize mitral valve regurgitation(MVR) due to insertion of the device 1000, the stabilizers 1012 may belocated approximately 120 degrees apart. This angle may be fixed oradjustably variable. The single-humped shape of the stabilizers 1012 mayallow the inferior portion 1030 to pass within the valve and applyradial pressure to the commissures CM and the superior portion 1032 (orhump) to rest upon and apply axial pressure to the commissures CM.

Referring again to FIG. 83, a pair of graspers, comprised of graspingsheaths 1020 and three opposing prongs 1021 configured to partially orfully penetrate or pierce, are shown extended from the conduit 1008 inthe plane bisecting the angle of the stabilizers 1012 (i.e. approachesthe middle of the leaflets). This angle may be fixed or variable. Whennot in use, however, the graspers may be fully retracted within theconduit 1008. Tension from lateral steering wires 1022 cause thegraspers to deflect away from each other and approximate the mostdesirable angle for grasping. Amount of deflection may be controlledfrom the proximal end of the device by the steering wires 1022. When thegraspers are positioned in a desired location as shown in FIG. 85, theprongs 1021 may be deployed and opened by either retraction of thegrasping sheath 1020 or advancement of the prongs 1021 beyond thegrasping sheath 1020. Retraction of the sheath 1020 does notsignificantly affect the position of the graspers, thus enabling theuser to contact the valve leaflets LF1, LF2 with the prongs 1021 housedwithin the sheath 1020 and then to initiate grasping the leaflets at thecontacted location by retracting the grasping sheaths 1020. The opposingprongs 1021 may be closed to grasp (pinch, partially penetrate orpierce) the leaflet tissue by advancing the grasping sheaths 1020 orretracting the prongs 1021 within the sheaths 1020.

After both leaflets have been grasped, tension in the steering wires1022 is released and the conduit 1008 is advanced over the graspingsheaths 1020. Such advancement draws the sheaths 1020, and graspedleaflets, together for coaptation. After coaptation, the mitral valveregurgitation is evaluated to determine if the locations which aregrasped are appropriate for fixation. If the grasping points are notappropriate, the leaflets may be released and regrasped individually orsimultaneously by the above described methods. If the grasping pointsare appropriate, the preferred embodiment allows for exchange of theguidewire, located in the guidewire lumen 1011, for a fixation device.The fixation device may use, for example, staples, sutures, clips,rivets, coils, fusing devices, zippers, snares, clamps, hooks, chordalfixation or shortening devices to repair the mitral valve regurgitation.Specifically, the fixation device may be the hollow suturing coil 1300shown previously in FIGS. 49A-C. As shown in FIG. 84A, the hollowsuturing coil 1300 containing suture 1302 (not shown) may be deployedthrough the guidewire lumen 1011 in a coiled configuration. The coil1300 may expand or change shape once it is deployed from the lumen 1011,providing the coil 1300 is comprised of a suitable shape memory orsuperelastic material. Similarly, as shown in FIG. 84B, the suturingcoil 1300 may be deployed through the guidewire lumen 1011 in astraightened configuration such that it coils and/or expands or changesshape once it is deployed from the lumen 1011.

The above described components may be manipulated and controlled by ahandle 1026 connected to the proximal end 1006 of the catheter shaft1002, as shown in FIG. 83. The handle 1026 permits independent controlof the components, including but not limited to retraction and extensionof extenders 1016, deployment of stabilizers 1012, adjustment andlocking of outer sheath 1010, translation and deflection of graspingsheaths 1020, stopping and locking of grasping sheaths 1020 and axialsliding of the conduit 1008. In addition, the device may be readilyadapted to approach the mitral valve trans-atrially for a minimallyinvasive surgical (MIS) procedure, with either beating or stopped heart.

B. Atrial-Ventricular Device

Referring to FIG. 86, the atrial-ventricular device 1100 is comprised ofa catheter shaft 1102 having a distal end 1104 and a proximal end 1106.The catheter shaft 1102 is comprised of, among others, a conduit 1108, acoaxial outer sheath 1110, a central lumen 1111 through which adouble-jaw grasper 1113 may be inserted, and a central guidewire lumen1105. Toward the distal end 1104, a pair of stabilizers 1112 having atriangular shape (previously illustrated in FIG. 31A) are fixedlymounted on the outer sheath 1110 at their proximal end 1114 and fixedlyattached to extenders 1116 at their distal end 1118. The stabilizers1112 are shown in an outwardly bowed position, however they may beinwardly collapsed by either extending the extenders 1116 or retractingthe outer sheath 1110. Bowing may be achieved by the reverse process.The double-jaw grasper 1113 is comprised of two articulating jaw arms1120 which may be opened and closed against the central shaft 1122(movement depicted by arrows) either independently or in tandem. Thegrasper 1113 is shown in the open position in FIG. 86. The surfaces ofthe jaw arms 1120 and central shaft 1122 may be toothed, as shown, ormay have differing surface textures for varying degrees of friction.

Referring to FIGS. 87A-C, the atrial-ventricular device 1100 may be usedwith a typical antegrade approach to the mitral valve MV, as previouslydescribed and depicted in FIGS. 7 and 8. However, the double-jaw grasper1113 extends through the valve such that the leaflets L1, L2 are graspedfrom below. Thus, the device 1100 is termed “atrial-ventricular.”

Referring to FIG. 87A, the atrial device 1100 may be stabilized againstthe mitral valve MV. The stabilizers 1112 may be positioned on thesuperior surface of the valve leaflets LF1, LF2 at a 90 degree angle tothe line of coaptation. The grasper 1113 may be advanced in its closedposition from the conduit 1108 between the leaflets LF1, LF2 until thejaw arms 1120 are fully below the leaflets in the ventricle. At thispoint, the grasper 1113 may be opened and retracted so that the jaw arms1120 engage the inferior surface of the leaflets LF1, LF2. In thismanner, the leaflets are secured between the stabilizers 1112 and thejaw arms 1120. This action allows for leaflets of many different shapesand orientations to be secured. Cardiomyopathic valves are oftenenlarged and distorted so that they coapt irregularly. Such irregularitycreates difficulty in mechanically coapting such valves for tissuemodification. The action of the grasper 1113 overcomes much of thesedifficulties.

Referring to FIG. 87B, the grasper 1113 will gradually close, drawingthe leaflets LF1, LF2 together while maintaining a secure hold on theleaflets between the jaw arms 1120 and the stabilizers 1112. This may beaccomplished by number of methods. For example, the stabilizers 1112 maybe gradually collapsed by either extending the extenders 1116 orretracting the outer sheath 1110. As the stabilizers 1112 collapse, thejaw arms 1120 may collapse due to spring loading to gradually close thegrasper 1113. Alternatively, the jaw arms 1120 may be actuated to closeagainst the central shaft 1122 applying force to the stabilizers 1112causing them to collapse. In either case, such action allows thestabilizers 1112 to simultaneously vertically retract and withdraw fromthe leaflets as the leaflets are clamped between the jaw arms 1120 andthe central shaft 1122. In this manner, the leaflets are effectively“transferred” to the grasper 1113. Referring to FIG. 87C, once thecollapsed stabilizers 1112 are completely withdrawn, the leaflets LF1,LF2 are held in vertical opposition by the grasper 1113 in a morenatural coaptation geometry. At this point the leaflets may be adjustedand fixated. Fixation may be achieved with an external element or thegrasper 1113 may be left in place as a fixation device.

The above described components may be manipulated and controlled by ahandle 1126 connected to the proximal end 1106 of the catheter shaft1102, as shown in FIG. 86. The handle 1026 permits independent controlof the components described above.

C. Ventricular Device

Referring to FIG. 88, the ventricular device 1200 is comprised of acatheter shaft 1202 having a distal end 1204 and a proximal end 1206.The distal end 1204 is comprised of a joining coil 1208, an upper jaw1210, a lower jaw 1212, an actuator 1214 and a central lumen 1216through which a guidewire 1218 or other wires may be inserted. The upperjaw 1210 may open and close (depicted by arrows) against the lower jaw1212 by action of the actuator 1214. The upper jaw 1210 is shown in theopen position. These components may be manipulated and controlled by ahandle 1226 connected to the proximal end 1206 of the catheter shaft1202 as shown.

Referring to FIGS. 89, the ventricular device 1200 may be used with atypical retrograde approach to the mitral valve MV, as previouslydescribed and depicted in FIG. 9. Here the mitral valve MV may beaccessed by an approach from the aortic arch AA across the aortic valveAV, and into the left ventricle LV below the mitral valve MV. Suchaccess may be maintained with a guide catheter 40 through which theventricular device 1200 may be introduced. The ventricular device 1200may be inserted through the guide catheter 40 with the upper jaw 1210 inthe closed position. After it exits the guide catheter 40 just below theaortic valve AV, the device 1200 may be advanced toward the mitral valveMV. The catheter shaft 1202 may be pre-shaped to provide favorablecurvature in positioning the distal end 1204 beneath the valve leafletsALF, PLF. Additionally, two mandrels with favorable shapes may beadvanced into a lumen in the catheter shaft 1202. By changing thelocation of the mandrels with respect to each other and to the cathetershaft 1202, the general curvature of the shaft 1202 may be altered insitu.

It is desired to position the distal end 1204 of the device 1200 beneaththe mitral valve leaflets ALF, PLF with the upper jaw 1210 in the openconfiguration. The lower jaw 1212 is to be proximal to the anteriorleaflet ALF and the upper jaw 1210 is to be distal of the posteriorleaflet PLF, as shown in FIG. 89, such that the leaflets may be securedbetween the jaws 1210, 1212. To achieve such positioning, the device1200 may be required to flex at an extreme angle in the region of thejoining coil 1208. Therefore, the joining coil 1208 is designed toprovide such flexibility.

To aid in positioning the device 1200, a balloon wire 1250 may be used.The balloon wire 1250 may first be inserted through the aortic valve AV,advanced down to the apex of the ventricle and then back upwards towardsthe mitral valve MV behind the posterior leaflet PLF. Once positioned,the balloon 1252 may be inflated to assist in holding the positionstationary. A cuff wire 1260 may then be inserted through the aorticvalve AV. The cuff wire 1260 may track along the balloon wire 1250 bymeans of a locking ring 1262. The cuff wire 1260 may track down to theapex of the ventricle and then back upwards toward the mitral valve MV.Once the cuff wire 1260 is advanced to a desirable position, the lockingring 1262 may be actuated to lock the cuff wire 1260 to the balloon wire1250. A typical means of actuation is by inflation of the locking ring.1262. The ventricular device 1200 may then be tracked over the cuff wire1260 to the desired position, as shown in FIG. 89. The balloon, orballoon wire 1250, may also be used to walk or urge the posteriorleaflet towards the center of the valve to facilitate grasping.

Once positioned, the upper jaw 1210 may be closed against the lower jaw1212 such that the leaflets are grasped between them. It is oftendesirable to adjust or manipulate the leaflets once they are grasped.Manipulation should occur only in a superior/inferior (up/down) motionin order to bring the leaflets to a final position where regurgitationis minimized. The lower jaw 1212 may be fitted with a travel mechanismfor extending or retracting the jaw 1212. This would move one leaflet upor down with respect to the other leaflet. Once the leaflets aresufficiently adjusted, fixation may occur in any manner previouslydescribed. In a preferred embodiment, fixation may achieved through thelower jaw 1212, as depicted in FIGS. 90A and 90B. As shown in FIG. 90A,a cutout 1270 may be present in the lower jaw 1212 accessing a lumen1272 which extends through the catheter shaft 1202 and lower jaw 1212;such a lumen may also serve as the guidewire lumen 1216. When the upperjaw 1210 is closed against the lower jaw 1212, the valve leaflets LF maybe captured between the jaws. As shown a side-view, FIG. 90B, thecaptured leaflets LF may protrude into through the cutout 1270 into thelumen 1272. A fixation device 1274 may then be inserted through thelumen 1272 (in the direction of the arrow) and may affix the leaflets LFtogether. It may be appreciated that such a method of fixation may beused in a number of devices involving jaw-type graspers, such as theatrial ventricular device 1100 depicted in FIG. 86.

Although the forgoing invention has been described in some detail by wayof illustration and example, for purposes of clarity of understanding,it will be obvious that various alternatives, modifications andequivalents may be used and the above description should not be taken aslimiting in scope of the invention which is defined by the appendedclaims.

1. A method of modifying a valve in a patient's heart to reduceregurgitation, the valve having an annulus, the method comprising:advancing a catheter comprising an interventional tool having an anchordeployment mechanism through the patient's vasculature into the heartfrom a femoral venous location, the anchor deployment mechanism carryinga plurality of deformable anchors; deploying the plurality of anchorsfrom the anchor deployment mechanism onto the annulus such that each ofthe deployed anchors penetrates a portion of the tissue of the annulus;threading a single filament through each of the deployed anchors suchthat the filament does not penetrate the tissue of the annulus; andtightening the filament so as to modify the annulus to reduceregurgitation in the valve.
 2. The method of claim 1, wherein thefilaments comprise sutures.
 3. The method of claim 1, wherein theanchors comprise staples.
 4. The method of claim 1, wherein advancingthe catheter comprises extending the catheter across an inter-atrialseptum of the heart.
 5. The method of claim 1, wherein the valve is amitral valve, and wherein tightening the filament modifies the annulusto reduce regurgitation in the mitral valve.
 6. The method of claim 1,further comprising positioning a guide catheter through the patient'svasculature into the heart from the femoral venous location, and whereinadvancing the catheter comprises advancing the catheter through theguide catheter.
 7. The method of claim 1, wherein tightening thefilament comprises tightening the annulus.
 8. The method of claim 1,wherein tightening the filament comprises shortening the annulus.
 9. Themethod of claim 1, wherein tightening the filament comprisescircumferentially shortening the annulus.
 10. The method of claim 1,wherein tightening the filament comprises circumferentially tighteningthe filament by drawing at least some of the anchors together.
 11. Themethod of claim 1, wherein tightening the filament comprisescircumferentially tightening the filament by plicating portions of theannulus.